Condensed Consolidated Statements of Changes in Unitholders' Capital - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Increase (decrease) in Stockholders' Equity:
Unitholders' capital, value			$ 1,808,094	$ 1,840,130
Cumulative-effect adjustment from adoption of accounting guidance			(122,621)
Issuance of units, value				237,820
Purchase of OCGH units from OCGH unitholders				(237,820)
Deferred tax effect resulting from the purchase of OCGH units				11,025
Repurchase and cancellation of units			(11,504)	(4,512)
Equity reallocation between controlling and non-controlling interests	$ (3,766)	$ (2,496)	(11,892)	(47,698)
Capital contributions				6,880
Capital increase related to equity-based compensation			48,247	38,959
Distributions declared			(289,914)	(306,047)
Net income			378,575	237,075
Foreign currency translation adjustment, net of tax	(272)	(1,411)	3,309	(2,539)
Unrealized gain on interest-rate swap designated as cash-flow hedge, net of tax	374	178	569	461
Unitholders' capital, value	1,814,755	1,821,432	1,814,755	1,821,432
Paid-in Capital
Increase (decrease) in Stockholders' Equity:
Unitholders' capital, value			735,166	536,431
Cumulative-effect adjustment from adoption of accounting guidance			(12,912)
Issuance of units, value				237,820
Purchase of OCGH units from OCGH unitholders				(237,820)
Deferred tax effect resulting from the purchase of OCGH units				11,025
Repurchase and cancellation of units			(11,191)
Equity reallocation between controlling and non-controlling interests			11,892	47,698
Capital increase related to equity-based compensation			19,488	12,023
Distributions declared			(1,350)	(8,319)
Unitholders' capital, value	741,093	598,858	741,093	598,858
Retained Earnings
Increase (decrease) in Stockholders' Equity:
Unitholders' capital, value			0	11,378
Distributions declared			(99,045)	(71,332)
Net income			135,422	59,954
Unitholders' capital, value	36,377	0	36,377	0
Accumulated Other Comprehensive Income (Loss)
Increase (decrease) in Stockholders' Equity:
Unitholders' capital, value			(1,216)	(1,070)
Foreign currency translation adjustment, net of tax			1,337	(738)
Unrealized gain on interest-rate swap designated as cash-flow hedge, net of tax			230	147
Unitholders' capital, value	351	(1,661)	351	(1,661)
Non-controlling Interests in Consolidated Subsidiaries
Increase (decrease) in Stockholders' Equity:
Unitholders' capital, value			1,043,930	1,265,961
Cumulative-effect adjustment from adoption of accounting guidance			(109,709)
Repurchase and cancellation of units			(313)	(4,512)
Equity reallocation between controlling and non-controlling interests			(11,892)	(47,698)
Capital contributions				4,000
Capital increase related to equity-based compensation			28,759	26,936
Distributions declared			(186,935)	(224,434)
Net income			241,785	174,377
Foreign currency translation adjustment, net of tax	(163)	(967)	1,972	(1,801)
Unrealized gain on interest-rate swap designated as cash-flow hedge, net of tax	223	122	339	314
Unitholders' capital, value	1,007,936	1,193,143	1,007,936	1,193,143
Non-controlling Interests in Consolidated Funds
Increase (decrease) in Stockholders' Equity:
Unitholders' capital, value			30,214	27,430
Capital contributions				2,880
Distributions declared			(2,584)	(1,962)
Net income			1,368	2,744
Foreign currency translation adjustment, net of tax	0	0	0	0
Unrealized gain on interest-rate swap designated as cash-flow hedge, net of tax	0	0	0	0
Unitholders' capital, value	$ 28,998	$ 31,092	$ 28,998	$ 31,092
Class A Units
Increase (decrease) in Stockholders' Equity:
Unitholders' capital, shares			61,970	43,764
Issuance of units, shares			1,240	4,908
Cancellation of units associated with forfeitures, shares			(51)
Cancellation of units, shares			(245)
Unitholders' capital, shares	62,914	48,672	62,914	48,672
Class B Units
Increase (decrease) in Stockholders' Equity:
Unitholders' capital, shares			91,938	109,089
Issuance of units, shares			630	1,338
Cancellation of units associated with forfeitures, shares			(111)	(105)
Cancellation of units, shares			(418)	(5,004)
Unitholders' capital, shares	92,039	105,318	92,039	105,318