Accounts Payable, Accrued Expenses and Other Liabilities (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Principal components of accounts payable, accrued expenses and other liabilities recorded on consolidated balance sheet
Accounts payable and accrued expenses	$ 21,507	$ 34,931
Deferred federal income tax liability	48,217	40,410	24,114
Accrued interest payable	38,273	27,849
Lease discounts, net of amortization of $30,830 and $7,328 respectively	596	2,242
Total accounts payable, accrued expenses and other liabilities	108,593	105,432
Accounts Payable, Accrued Expenses and Other Liabilities (Textual) [Abstract]
Accumulated amortization recorded on operating lease discounts	$ 30,830	$ 7,328