Noncontrolling Interests (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Summary of redeemable noncontrolling interests
Noncontrolling interest expense, Income Statement Impact	$ 1,088	$ 1,172
Noncontrolling Interests [Roll Forward]
Redeemable noncontrolling interests, beginning balance	11,077
Redemption value change	1,392	723
Purchase of noncontrolling interests	(690)	29
Distribution to noncontrolling interests	(1,784)	(1,627)
Redeemable noncontrolling interests, ending balance	11,273
Mandatorily Redeemable Noncontrolling Interests [Member]
Summary of redeemable noncontrolling interests
Noncontrolling interest expense, Income Statement Impact	1,088	1,172
Redemption value change, Income Statement Impact	1	315
Noncontrolling Interests [Roll Forward]
Redeemable noncontrolling interests, beginning balance	9,405	9,355
Redemption value change	1,089	1,487
Purchase of noncontrolling interests	(803)
Distribution to noncontrolling interests	(1,099)	(1,064)
Currency translation adjustment	(338)	(358)
Redeemable noncontrolling interests, ending balance	8,254	9,420
Redeemable Noncontrolling Interests [Member]
Summary of redeemable noncontrolling interests
Noncontrolling interest expense, Income Statement Impact	1,021	940
Redemption value change, Income Statement Impact	371	(217)
Noncontrolling Interests [Roll Forward]
Redeemable noncontrolling interests, beginning balance	11,077	10,678
Redemption value change	1,392	723
Formation of noncontrolling interests		855
Purchase of noncontrolling interests		(356)
Distribution to noncontrolling interests	(1,196)	(886)
Redeemable noncontrolling interests, ending balance	$ 11,273	$ 11,014