Equity Investments in the Managed Programs and Real Estate - Summarized Income Statement for Equity Investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Combined Equity Investments
Equity Method Investment Summarized Financial Information Income Statement
Revenues	$ 56,791	$ 61,887	$ 64,294
Expenses	(17,933)	(21,124)	(27,801)
Income from continuing operations	38,858	40,763	36,493
Net income (loss) attributable to equity investments	38,858	40,763	36,493
Managed Programs
Equity Method Investment Summarized Financial Information Income Statement
Revenues	1,465,803	1,157,432	825,405
Expenses	(1,265,819)	(1,129,294)	(816,630)
Income from continuing operations	199,984	28,138	8,775
Net income (loss) attributable to equity investments	$ 145,936	$ (15,740)	$ (12,695)