Notes Payable (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Interest incurred and expensed on the notes payable
Gain on derivatives, net	$ (100)	$ (300)	$ (234)	$ (417)
Accretion of Senior Notes				3
Total interest incurred and expensed on the notes payable	18,331	17,272	36,614	34,686
Notes payable
Interest incurred and expensed on the notes payable
Interest expense on debt and capital lease obligations	17,720	16,807	35,376	33,617
Gain on derivatives, net	(125)	(260)	(234)	(417)
Accretion of Senior Notes				3
Amortization of deferred financing fees	736	725	1,472	1,483
Total interest incurred and expensed on the notes payable	$ 18,331	$ 17,272	$ 36,614	$ 34,686