Fair Value Measurements and Interest Rate Swaps (Tables)

3 Months Ended

Mar. 31, 2015

Derivative [Line Items]

Estimated fair value of swap contracts

The table below presents the estimated fair value of our interest rate swap contracts and our forward-starting interest rate swap contracts (in thousands):

	Fair Value at
	March 31,
Level 2	2015			2014
Unrealized losses on interest rate swaps	$	(3,728	)	$	(1,520	)

Interest Rate Swap Agreements[Member]

Derivative [Line Items]

Schedule of Interest Rate Derivatives

The following table provides additional details related to each of these swap contracts:

Derivative	Effective Date	Notional Amount (in millions)	Fixed Interest Rate
Interest rate swap 1	November 21, 2011	$25.0	1.185%
Interest rate swap 2	November 21, 2011	$25.0	1.185%
Interest rate swap 3	December 21, 2011	$50.0	1.100%
Interest rate swap 4	January 17, 2012	$25.0	1.050%
Interest rate swap 5	January 19, 2012	$25.0	0.990%

Forward-Starting Interest Rate Swap Agreements[Member]

Derivative [Line Items]

Schedule of Interest Rate Derivatives

The following table provides additional details related to each of these swap contracts:

Derivative	Inception Date	Notional Amount (in millions)	Fixed Interest Rate
Forward-starting interest rate swap 1	May 8, 2014	$25.0	2.520%
Forward-starting interest rate swap 2	May 14, 2014	$50.0	2.450%
Forward-starting interest rate swap 3	May 19, 2014	$50.0	2.339%
Forward-starting interest rate swap 4	May 28, 2014	$25.0	2.256%