Noncontrolling Interests - Summary of Mandatorily Redeemable Noncontrolling Interests in Other Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Mandatorily Redeemable Noncontrolling Interests [Roll Forward]
Beginning balance, Redeemable Noncontrolling Interests	$ 11,077
Redemption value change	958	$ 1,210	$ 1,233
Purchase of noncontrolling interests	(690)	30	(5,094)
Distribution to noncontrolling interests	(2,468)	(2,281)	(1,886)
Ending balance, Redeemable Noncontrolling Interests	11,511	11,077
Securities Subject to Mandatory Redemption [Member]
Summary of redeemable noncontrolling interests
Noncontrolling interest expense, Income Statement Impact	1,447	1,625	2,003
Redemption value change, Income Statement Impact	229	312	74
Mandatorily Redeemable Noncontrolling Interests [Roll Forward]
Beginning balance, Redeemable Noncontrolling Interests	9,405	9,355	11,047
Redemption value change	1,676	1,937	2,077
Formation of noncontrolling interests			80
Purchase of noncontrolling interests	(803)		(1,703)
Dissolution of noncontrolling interests			(357)
Distribution to noncontrolling interests	(1,250)	(1,418)	(1,833)
Currency translation adjustment	(440)	(469)	44
Ending balance, Redeemable Noncontrolling Interests	8,588	9,405	9,355
Redeemable Partnership Interests [Member]
Summary of redeemable noncontrolling interests
Noncontrolling interest expense, Income Statement Impact	958	1,226	1,146
Redemption value change, Income Statement Impact	0	(16)	87
Mandatorily Redeemable Noncontrolling Interests [Roll Forward]
Beginning balance, Redeemable Noncontrolling Interests	11,077	10,678	6,991
Redemption value change	958	1,210	1,233
Formation of noncontrolling interests	2,062	855	3,601
Purchase of noncontrolling interests	(1,007)	(356)
Distribution to noncontrolling interests	(1,579)	(1,310)	(1,147)
Ending balance, Redeemable Noncontrolling Interests	$ 11,511	$ 11,077	$ 10,678