Investments in Unconsolidated Entities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Reconciliation of members' and partners' equity to the Company's Carrying Value
Total members’ and partners’ equity	$ 1,234,612		$ 798,590
Equity of other members and partners	1,079,695		777,646
Company’s net investment in unconsolidated entities	154,917		20,944
Basis differences	238,606	[1]	137,259	[1]
Advances to and on behalf of affiliates	15,450		32,119
Assets - Investments in and advances to unconsolidated entities	620,466		447,165
Liabilities - Cash distributions and losses in excess of investments in unconsolidated entities	(211,493)		(256,843)
Total Investments in Unconsolidated Entities, net	$ 408,973		$ 190,322

[1] Represents the aggregate difference between the Company’s historical cost basis and the basis reflected at the equity method venture level, which is typically amortized over the life of the related assets or liabilities. Basis differences relate to certain acquisition, transaction and other costs, as well as other-than-temporary impairments not reflected in the net assets at the equity method venture level.