Financing Activity - Additional Information (Detail) (USD $)	3 Months Ended			3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended		3 Months Ended											3 Months Ended							0 Months Ended					3 Months Ended
	Mar. 31, 2014 Extension	Mar. 31, 2013	Dec. 31, 2013	Mar. 31, 2013 2010 Term Loan [Member]	Jan. 08, 2014 Two Thousand Fourteen Term Loans [Member]	Mar. 31, 2014 Two Thousand Fourteen Term Loans [Member]	Jan. 08, 2014 Two Thousand Fourteen Term Loans [Member] Minimum [Member]	Jan. 08, 2014 Two Thousand Fourteen Term Loans [Member] Maximum [Member]	Mar. 31, 2014 Two Thousand Fourteen Term Loans and Two Thousand Thirteen Revolving Facility [Member]	Mar. 31, 2014 Two Thousand Fourteen Term Loans and Two Thousand Thirteen Revolving Facility [Member] Minimum [Member]	Mar. 31, 2014 Two Thousand Fourteen Term Loans and Two Thousand Thirteen Revolving Facility [Member] Maximum [Member]	Mar. 31, 2014 2013 Revolving Credit Facility [Member]	Mar. 31, 2014 2013 Revolving Credit Facility [Member] Minimum [Member]	Mar. 31, 2014 2013 Revolving Credit Facility [Member] Minimum [Member] LIBOR [Member]	Mar. 31, 2014 2013 Revolving Credit Facility [Member] Maximum [Member]	Mar. 31, 2014 2013 Revolving Credit Facility [Member] Maximum [Member] LIBOR [Member]	Mar. 31, 2014 2013 Revolving Credit Facility [Member] First Extension [Member]	Mar. 31, 2014 2013 Revolving Credit Facility [Member] Second Extension [Member]	Apr. 16, 2013 2010 Credit Facility [Member]	Mar. 31, 2013 Revolving Credit Facility [Member]	Mar. 31, 2013 Line of Credit [Member]	Apr. 16, 2013 2010 Term Loan [Member]	Mar. 31, 2014 Five Year Term Loan [Member]	Mar. 31, 2014 Seven Year Term Loan [Member]	Mar. 31, 2014 Wells Fargo Bank , NA [Member] 2013 Revolving Credit Facility [Member]	Apr. 17, 2013 Wells Fargo Bank , NA [Member] 2013 Revolving Credit Facility [Member]	Jan. 08, 2014 Wells Fargo Bank, NA and Capital One, NA [Member] Seven Year Term Loan [Member]	Jan. 08, 2014 Wells Fargo Bank, NA and US Bank N [Member] Five Year Term Loan [Member]	Jan. 08, 2014 London Interbank Offered Rate (LIBOR) [Member] Wells Fargo Bank, NA and Capital One, NA [Member] Seven Year Term Loan [Member]	Jan. 08, 2014 London Interbank Offered Rate (LIBOR) [Member] Wells Fargo Bank, NA and US Bank N [Member] Five Year Term Loan [Member]	Mar. 31, 2014 Springfield Town Center [Member]	Mar. 31, 2014 Ratio One [Member] London Interbank Offered Rate (LIBOR) [Member] Wells Fargo Bank , NA [Member] Revolving Credit Facility [Member]	Mar. 31, 2014 Ratio One [Member] London Interbank Offered Rate (LIBOR) [Member] Wells Fargo Bank, NA and Capital One, NA [Member] Seven Year Term Loan [Member]	Mar. 31, 2014 Ratio One [Member] London Interbank Offered Rate (LIBOR) [Member] Wells Fargo Bank, NA and US Bank N [Member] Five Year Term Loan [Member]
Debt Instrument [Line Items]
Unsecured Debt																							$ 100,000,000	$ 30,000,000
Debt Instrument, Face Amount					250,000,000																						100,000,000	150,000,000.0
Debt Instrument, Term																											7 years	5 years
Senior Unsecured Credit Facility																									400,000,000	400,000,000.0
Amount outstanding	25,000,000		130,000,000									25,000,000										97,500,000
Unused portion of line of credit												375,000,000
Interest expense excluding non-cash amortization of finance costs				2,200,000		900,000						500,000								300,000
Non-cash amortization of deferred financing fees						100,000						400,000									700,000
Line of Credit Facility, Deferred Draw Period, Maximum					1 year
Revolving Credit Facility Extension Options Available	2
Outstanding commitments																	0.15%	0.20%
Weighted average interest rate of Term Loan				3.95%								1.85%		1.50%		2.05%
Stated Interest Rate												1.70%
Capitalization rate used to calculate Gross Asset Value							6.50%	7.50%					6.50%		7.50%
Debt Instrument, Basis Spread on Variable Rate																													1.95%	1.45%		1.50%	1.80%	1.35%
Sales Per Square Foot					500							500
Percentage of unused portion of the 2013 Revolving Facility												0.30%															0.35%	0.20%
Maximum amount available under revolving facility through accordion option																									600,000,000		200,000,000	300,000,000
Line of Credit Facility, Accordion Option, Minimum Incremental Increase												5,000,000															5,000,000	5,000,000
Line of Credit Facility, Accordion Option, Minimum Increase												25,000,000															25,000,000	25,000,000
Minimum tangible net worth									75.00%
Net proceeds of equity issuances									75.00%
Maximum secured indebtedness										0.60	0.625
Maximum Investments in Persons other than Subsidiaries, Consolidated Affiliates and Unconsolidated Affiliates									5.00%
Maximum Mortgages in Favor of the Borrower or any other Subsidiary									5.00%
Maximum Aggregate Value of Investments to Gross Asset Value									10.00%
Maximum Investments in Consolidation Exempt Entities to Gross Asset Value									25.00%
Maximum Projects Under Development to Gross Asset Value									15.00%
Aggregate of Consolidation Exempt Entities and Projects to Gross Asset Value									35.00%
Minimum ratio of Adjusted EBITDA to Fixed Charges										1.45	1.50
Unencumbered Debt Yield									12.00%
Investment Percentage of Gross Asset Value									1.75
Maximum Ratio of Secured Indebtedness to Gross Asset Value									0.60
Investment Percentage of Gross Asset Value					2.50%
Percentage of distribution related to FFO									95.00%
REIT Taxable Income distributions									110.00%
Line of Credit Facility, Maximum Borrowing Capacity																			250,000,000.0								100,000,000.0	150,000,000.0
Repayment of outstanding amount under revolving facility	(130,000,000)	84,500,000
Debt Instrument, Number of Loan Entered During Period					2
Accelerated amortization of deferred financing fees																					800,000
Permanent repayments of 2010 Term Loan																				84,500,000
Minimum Percentage of Total Guarantors Required to be Guarantors Based on Gross Asset Value									95.00%
Letters of Credit Outstanding, Amount																															$ 46,500,000
Letter of Credit, Initial Fee in Effect																															1.15%
Line of Credit Facility, Prepayment Penalty, Next Twelve Months																											3.00%
Line of Credit Facility, Prepayment Penalty, Year Two																											2.00%
Line of Credit Facility, Prepayment Penalty, Year Three																											1.00%
Debt Instrument, Interest Rate at Period End																							1.60%	2.10%