Non-controlling Interests (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Variable Interest Entity [Line Items]
Net income of consolidated entities attributable to non-controlling interests	$ 21,488	$ 6,375	$ 456
Non-redeemable non-controlling interest	36,172	24,473
Redeemable non-controlling interest	392,959	13,203
CPH Acquisition [Member]
Variable Interest Entity [Line Items]
Redeemable non-controlling interest	8,665	13,203
Consolidated Private Equity Fund [Member]
Variable Interest Entity [Line Items]
Net income of consolidated entities attributable to non-controlling interests	0	5,940	487
Non-redeemable non-controlling interest	0	23,171
Other Investments [Member]
Variable Interest Entity [Line Items]
Net income of consolidated entities attributable to non-controlling interests	312	435	(31)
Non-redeemable non-controlling interest	1,550	1,302
Consolidated VIEs [Member]
Variable Interest Entity [Line Items]
Net income of consolidated entities attributable to non-controlling interests	21,176	0	$ 0
Non-redeemable non-controlling interest	34,622	0
Redeemable non-controlling interest	$ 384,294	$ 0