Fair Value Measurement - Summary of Activity for Account Balances Whose Fair Value Measurements are Estimated Utilizing Level 3 Inputs (Details) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Redeemable Noncontrolling Interests [Roll Forward]
Net income (loss)	$ 491,237	$ 412,299
Fair value adjustments	2,162	(1,081)
Redeemable Noncontrolling Interests (Temporary Equity) [Member]
Redeemable Noncontrolling Interests [Roll Forward]
Beginning period balance	99,000	96,251	$ 96,251
Net income (loss)	2,162	3,747	(2,760)
Fair value adjustments	(2,162)	$ 1,081	17,794
Dividends paid to non-controlling interests			(12,985)
Additions to non-controlling interests			700
Purchase of non-controlling interest	$ (99,000)
Ending period balance			$ 99,000