Previously Consolidated Variable Interest Entities (Details 13) (Previously Consolidated Variable Interest Entities, Interest Rate Swaps, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011
Previously Consolidated Variable Interest Entities | Interest Rate Swaps
Amount of loss recognized in OCI	$ (10,449)	[1]	$ (3,587)	[1]
Amount of loss reclassified from OCI to income	$ (15,066)	[2]	$ (15,593)	[2]

[1] Represents the amount of unrealized gains and losses recorded to other comprehensive income during the period, net of the amount reclassified to interest expense.

[2] Represents net amounts paid to swap counterparties during the period, which are included in interest expense, offset by an immaterial amount of non-cash swap amortization.