XML 53 R89.htm IDEA: XBRL DOCUMENT v2.4.1.9
Share-Based Compensation (Details 1) (USD $)
In Millions, except Share data, unless otherwise specified
0 Months Ended 12 Months Ended
Apr. 04, 2013
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Allocated Share-based Compensation Expense   $ 14.5us-gaap_AllocatedShareBasedCompensationExpense $ 9.6us-gaap_AllocatedShareBasedCompensationExpense $ 8.5us-gaap_AllocatedShareBasedCompensationExpense
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]        
Granted (in shares)   236,604us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod    
Restricted Stock [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]        
Outstanding at beginning of year, Weighted Average Grant Date Fair Value (in dollars per share)   $ 41.71us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
   
Granted (in shares)     0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
62,137us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
Grant date fair value per share   $ 51.35us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
$ 0.00us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
$ 41.84us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
Vested (in shares)     (47,291)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
(50,862)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
Outstanding at end of year, Weighted Average Grant Date Fair Value (in dollars per share)   $ 47.05us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
$ 41.71us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
 
Market Measure-Based Restricted Stock Units (RSUs) [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]        
Outstanding at beginning of year, Weighted Average Grant Date Fair Value (in dollars per share)   $ 46.47us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
[1]    
Granted (in shares)   119,098us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
   
Grant date fair value per share   $ 64.86us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
[1] $ 44.55us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
$ 41.20us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value   $ 41.53us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
[1]    
Outstanding at end of year, Weighted Average Grant Date Fair Value (in dollars per share)   $ 58.77us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
[1] $ 46.47us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
[1]  
Time-Based Restricted Stock Units (RSUs) [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]        
Outstanding at beginning of year, Weighted Average Grant Date Fair Value (in dollars per share)   $ 44.74us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
[2]    
Outstanding at beginning of year, Vested RSUs   1,158,407krc_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedNumber
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
[3]    
Granted (in shares)   117,506us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
   
Grant date fair value per share   $ 59.89us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
[2] $ 49.45us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
$ 44.34us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value   $ 47.64us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
[2]    
Modified from time based, Weighted Average Grant Date Fair Value (in dollars per share) $ 48.88krc_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsModifiedinPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
[2]      
Outstanding at end of year, Weighted Average Grant Date Fair Value (in dollars per share)   $ 51.04us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
$ 44.74us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
[2]  
Outstanding at end of year, Vested RSUs   1,248,352krc_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedNumber
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
[3] 1,158,407krc_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedNumber
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
[3]  
Restricted Stock Units (RSUs) [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]        
Outstanding at beginning of year, Total RSUs   143,022us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber
/ krc_AwardFeatureAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
   
Granted (in shares)   183,365us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ krc_AwardFeatureAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
   
Vested (in shares)   0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ krc_AwardFeatureAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
   
Settled (in shares)   (16,338)us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross
/ krc_AwardFeatureAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
   
Modified from time based (in shares)   31,455krc_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsModifiedinPeriod
/ krc_AwardFeatureAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
   
Outstanding at beginning of year, Total RSUs   247,089us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber
/ krc_AwardFeatureAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
   
Restricted Stock Units (RSUs) [Member] | Time-Based Restricted Stock Units (RSUs) [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]        
Outstanding at beginning of year, Total RSUs   1,158,407us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber
/ krc_AwardFeatureAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
   
Granted (in shares)   155,016us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ krc_AwardFeatureAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
   
Vested (in shares)   0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ krc_AwardFeatureAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
[4],[5]    
Outstanding at beginning of year, Total RSUs   1,248,352us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber
/ krc_AwardFeatureAxis
= us-gaap_RestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
   
Nonvested Restricted Stock Units R S U [Member] | Restricted Stock [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]        
Outstanding at beginning of year (in shares)   47,950us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ krc_AwardFeatureAxis
= krc_NonvestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
   
Granted (in shares)   213us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ krc_AwardFeatureAxis
= krc_NonvestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
   
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value   $ 45.56us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue
/ krc_AwardFeatureAxis
= krc_NonvestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
[6]    
Modified from time based (in shares)   (62,797)krc_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsModifiedinPeriod
/ krc_AwardFeatureAxis
= krc_NonvestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
[6]    
Modified from time based, Weighted Average Grant Date Fair Value (in dollars per share)   $ 50.97krc_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsModifiedinPeriodWeightedAverageGrantDateFairValue
/ krc_AwardFeatureAxis
= krc_NonvestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
[6]    
Outstanding at end of year (in shares)   85,061us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ krc_AwardFeatureAxis
= krc_NonvestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
   
Nonvested Restricted Stock Units R S U [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]        
Granted (in shares)   183,365us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ krc_AwardFeatureAxis
= krc_NonvestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
[7] 9,542us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ krc_AwardFeatureAxis
= krc_NonvestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
103,239us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ krc_AwardFeatureAxis
= krc_NonvestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
Outstanding at end of year (in shares)   247,089us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ krc_AwardFeatureAxis
= krc_NonvestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
   
Nonvested Restricted Stock Units R S U [Member] | Time-Based Restricted Stock Units (RSUs) [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]        
Outstanding at beginning of year (in shares)   301,660us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ krc_AwardFeatureAxis
= krc_NonvestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
   
Granted (in shares)   155,016us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ krc_AwardFeatureAxis
= krc_NonvestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
[8] 173,758us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ krc_AwardFeatureAxis
= krc_NonvestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
204,829us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ krc_AwardFeatureAxis
= krc_NonvestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
Cancelled (in shares)   (3,992)us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation
/ krc_AwardFeatureAxis
= krc_NonvestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
[9]    
Outstanding at end of year (in shares)   340,997us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ krc_AwardFeatureAxis
= krc_NonvestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
301,660us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ krc_AwardFeatureAxis
= krc_NonvestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
 
Vested Restricted Stock Units R S U [Member] | Restricted Stock [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]        
Vested (in shares)   (25,899)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ krc_AwardFeatureAxis
= krc_VestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
[6]    
Cancelled (in shares)   (11,020)us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation
/ krc_AwardFeatureAxis
= krc_VestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
   
Vested Restricted Stock Units R S U [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]        
Outstanding at beginning of year, Vested RSUs   0krc_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedNumber
/ krc_AwardFeatureAxis
= krc_VestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
   
Granted (in shares)   0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ krc_AwardFeatureAxis
= krc_VestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
   
Vested (in shares)   (16,338)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ krc_AwardFeatureAxis
= krc_VestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
[10] (16,338)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ krc_AwardFeatureAxis
= krc_VestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
(14,748)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ krc_AwardFeatureAxis
= krc_VestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
Settled (in shares)   (16,338)us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross
/ krc_AwardFeatureAxis
= krc_VestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
[11]    
Modified from time based (in shares)   0krc_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsModifiedinPeriod
/ krc_AwardFeatureAxis
= krc_VestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
   
Cancelled (in shares)   (8,526)us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation
/ krc_AwardFeatureAxis
= krc_VestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
   
Outstanding at end of year, Vested RSUs   0krc_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedNumber
/ krc_AwardFeatureAxis
= krc_VestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
0krc_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedNumber
/ krc_AwardFeatureAxis
= krc_VestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
 
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Period Increase (Decrease)   0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsPeriodIncreaseDecrease
/ krc_AwardFeatureAxis
= krc_VestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_MarketMeasureBasedRestrictedStockUnitsRsusMember
   
Vested Restricted Stock Units R S U [Member] | Time-Based Restricted Stock Units (RSUs) [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]        
Outstanding at beginning of year, Vested RSUs   856,747krc_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedNumber
/ krc_AwardFeatureAxis
= krc_VestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
   
Granted (in shares)   0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ krc_AwardFeatureAxis
= krc_VestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
   
Vested (in shares)   (116,447)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ krc_AwardFeatureAxis
= krc_VestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
[4],[5] (89,873)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ krc_AwardFeatureAxis
= krc_VestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
(73,688)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ krc_AwardFeatureAxis
= krc_VestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
Settled (in shares)   (61,242)us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross
/ krc_AwardFeatureAxis
= krc_VestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
   
Cancelled (in shares)   (5,694)us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation
/ krc_AwardFeatureAxis
= krc_VestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
   
Outstanding at end of year, Vested RSUs   907,355krc_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedNumber
/ krc_AwardFeatureAxis
= krc_VestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
856,747krc_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedNumber
/ krc_AwardFeatureAxis
= krc_VestedRestrictedStockUnitsRSUMember
/ us-gaap_AwardTypeAxis
= krc_TimeBasedRestrictedStockUnitsRsusMember
 
Executive Officer Share-Based Compensation Programs [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]        
Modified from time based, Weighted Average Grant Date Fair Value (in dollars per share) $ 53.05krc_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsModifiedinPeriodWeightedAverageGrantDateFairValue
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[1],[2]      
Executive Officer Share-Based Compensation Programs [Member] | Restricted Stock Units (RSUs) [Member] | Time-Based Restricted Stock Units (RSUs) [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Period Increase (Decrease) (31,292)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsPeriodIncreaseDecrease
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[12]      
Executive Officer Share-Based Compensation Programs [Member] | Nonvested Restricted Stock Units R S U [Member] | Market Measure-Based Restricted Stock Units (RSUs) [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]        
Modified from time based (in shares) 31,455krc_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsModifiedinPeriod
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[13],[14]      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Period Increase (Decrease) (31,505)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsPeriodIncreaseDecrease
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[15]      
Executive Officer Share-Based Compensation Programs [Member] | Nonvested Restricted Stock Units R S U [Member] | Time-Based Restricted Stock Units (RSUs) [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Period Increase (Decrease) (30,687)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsPeriodIncreaseDecrease
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[12]      
Executive Officer Share-Based Compensation Programs [Member] | Vested Restricted Stock Units R S U [Member] | Time-Based Restricted Stock Units (RSUs) [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Period Increase (Decrease) (605)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsPeriodIncreaseDecrease
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[15]      
[1] Represents the grant-date fair value for all awards excluding the 2014 Performance-Based RSU Grant. As discussed above, the 2014 Performance-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.
[2] Represents the grant-date fair value for all awards excluding the 2014 Time-Based RSU Grant. As discussed above, the 2014 Time-Based RSU Grant was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014.
[3] The amount includes nonvested RSUs. Does not include the 247,089 and 143,022 market measure-based RSUs since not all the necessary performance conditions have been met as of December 31, 2014 and 2013, respectively.
[4] (3)Includes dividend equivalents vested in accordance with the award agreements.
[5] (4)Represents vested RSUs that were settled in shares of the Company’s common stock. Total shares settled include 5,694 shares that were tendered in accordance with the terms of the 2006 Plan to satisfy minimum statutory tax withholding requirements related to the RSUs settled. We accept the return of RSUs at the current quoted closing share price of the Company’s common stock to satisfy tax obligations.
[6] The total shares vested include 11,020 shares that were tendered in accordance with the terms of the 2006 Plan to satisfy minimum statutory tax withholding requirements related to the restricted shares that have vested. We accept the return of shares at the current quoted closing share price of the Company’s common stock to satisfy tax obligations.
[7] Includes dividend equivalents issued in accordance with the award agreements.
[8] (2)Includes dividend equivalents issued in accordance with the award agreements.
[9] (5)For shares vested but not yet settled, we accept the return of RSUs at the current quoted closing share price of the Company’s common stock to satisfy minimum statutory tax-withholding requirements related to either the issuance or vesting of RSUs in accordance with the terms of the 2006 Plan.
[10] Includes dividend equivalents vested in accordance with the award agreements.
[11] Represents vested RSUs that were settled in cash or shares of the Company’s common stock. Total shares settled include 8,526 shares that were tendered in accordance with the terms of the 2006 Plan to satisfy minimum statutory tax withholding requirements related to the RSUs settled. We accept the return of RSUs, at the current quoted closing share price of the Company’s common stock to satisfy tax obligations.
[12] (7)During January 2014, RSUs were transferred to restricted stock based on the elected distribution date.
[13] (6)On January 29, 2014, the market-measure requirements related to the RSU awards granted in 2013 were met. As of December 31, 2014 the awards are only subject to time-based vesting requirements.
[14] On January 29, 2014, the market-measure requirements related to the RSU awards granted in 2013 were met, and as a result, the shares were transferred to time-based restricted stock units since at that point the awards became subject to only time-based vesting requirements pursuant to the award agreements.
[15] On January 29, 2014, the market-measure requirements related to the RSU award were met and, as a result, the RSUs were transferred to restricted stock based on the employee’s distribution election and remain subject to time-based vesting requirements pursuant to the award agreement.