Fair Value of Assets and Liabilities (Tables)

3 Months Ended

Mar. 31, 2014

Fair Value of Assets and Liabilities

Schedule of assets and liabilities measured at fair value

				Fair Value at Reporting Date Using
				Quoted Prices in					Significant
				Active Markets for		Significant Other			Unobservable
				Identical Assets		Observable Inputs			Inputs
Description	Total			(Level 1)		(Level 2)			(Level 3)
Recurring Fair Value Measurements:
Effective portion of interest rate swap contracts(1)	$	(10,706	)	$	—	$	(10,706	)	$	—
Non-Recurring Fair Value Measurements:
Properties held for sale(2)	$	213,244		$	—	$	—		$	213,244

(1) The fair value of our interest rate swap contracts is determined using the net discounted cash flows of the expected cash flows of each derivative based on the market based interest rate curve (level 2 inputs) and adjusted for our credit spread and the actual and estimated credit spreads of the counterparties (level 3 inputs).  Although we have determined that the majority of the inputs used to value our derivatives fall within level 2 of the fair value hierarchy, the credit valuation adjustments associated with our derivatives utilize level 3 inputs, such as estimates of current credit spreads, to evaluate the likelihood of default by us and the counterparties.  As of March 31, 2014, we have assessed the significance of the impact of the credit valuation adjustments on the overall valuation of our derivative positions and have determined that the credit valuation adjustments are not significant to the overall valuation of our derivatives.  As a result, we have determined that our derivative valuations in their entirety are classified as level 2 inputs in the fair value hierarchy.

(2) As of March 31, 2014, we recorded a loss on asset impairment totaling $288 for one of our CBD properties (two buildings) and 13 of our suburban properties (41 buildings) to reduce the aggregate carrying value of these properties from $213,532 to their estimated fair value of $218,000, reflected in the table below, or $213,244 net of costs to sell.  All of these properties were classified as held for sale as of December 31, 2013.  We used current contracted sale prices (level 3 inputs) in determining the fair value of these properties.  The valuation techniques and significant unobservable inputs used for our level 3 fair value measurements at March 31, 2014 were as follows:

Description	Fair Value at March 31, 2014		Primary Valuation Techniques	Unobservable Inputs	Range (Weighted Average)
Properties held for sale on which we recognized impairment losses	$	218,000	Current Contracted Sale Prices	N/A	N/A

Schedule of valuation techniques and significant unobservable inputs used for level 3 fair value measurements

Description	Fair Value at March 31, 2014		Primary Valuation Techniques	Unobservable Inputs	Range (Weighted Average)
Properties held for sale on which we recognized impairment losses	$	218,000	Current Contracted Sale Prices	N/A	N/A

Schedule of effects of interest rate derivatives on our condensed consolidated statements of operations and condensed consolidated statements of comprehensive income

	Three Months Ended March 31,
	2014			2013
Balance at beginning of period	$	(11,706	)	$	(16,624	)
Amount of loss recognized in cumulative other comprehensive income	(229		)	(185		)
Amount of loss reclassified from cumulative other comprehensive income into interest expense	1,229			1,236
Unrealized gain on derivative instruments	1,000			1,051
Balance at end of period	$	(10,706	)	$	(15,573	)

Fair value and carrying value of financial instruments

	March 31, 2014				December 31, 2013
	Carrying		Fair		Carrying		Fair
	Amount		Value		Amount		Value
Senior notes and mortgage notes payable	$	2,082,117	$	2,174,291	$	2,097,164	$	2,143,834