Commitments and Contingencies (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Commitments And Contingencies [Line Items]
Beginning interest payable, Total	$ 7,989	$ 5,364
Interest incurred, Total	24,541	18,001
Interest payments, Total	(23,813)	(16,763)
Ending interest payable, Total	8,706	6,602
Beginning interest payable, Cash	2,435	1,630
Interest incurred, Cash	7,499	5,500
Interest payments, Cash	(7,271)	(5,096)
Ending interest payable, Cash	2,663	2,034
Beginning interest payable, Deemed Loan	5,543	3,734
Interest incurred, Deemed Loan	17,042	12,501
Interest payments, Deemed Loan	(16,542)	(11,667)
Ending interest payable, Deemed Loan	$ 6,043	$ 4,568