CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Total	Preferred Stock Series A preferred stock	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest
Beginning Balance (in shares) at Dec. 31, 2013		0	85,500,000
Beginning Balance at Dec. 31, 2013	$ 1,767,538	$ 0	$ 855	$ 195,110	$ 1,610,964	$ (56,468)	$ 17,077
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	328,146				326,456		1,690
Currency translation adjustment	(82,871)					(80,221)	(2,650)
Change in qualifying cash flow hedge, net of tax	(1,730)					(1,730)
Issuance of common stock for exercise of options, restricted stock units and employee stock purchases (in shares)			1,061,000
Issuance of common stock for exercise of options, restricted stock units and employee stock purchases	58,562		$ 11	$ 58,551
Purchase and cancellation of treasury stock (in shares)			(1,677,000)
Purchase and cancellation of treasury stock	(194,066)		$ (17)		(194,049)
Stock compensation expense	17,773			$ 17,773
Excess tax benefit of stock options exercised	17,906			17,906
Noncontrolling interests attributable to acquisitions	6,781						6,781
Reduction to noncontrolling interests due to additional ownership	(854)			(129)			(725)
Ending Balance (in shares) at Dec. 31, 2014		0	84,884,000
Ending Balance at Dec. 31, 2014	1,917,185	$ 0	$ 849	289,211	1,743,371	(138,419)	22,173
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	189,426				188,170		1,256
Currency translation adjustment	(95,155)					(95,291)	136
Change in qualifying cash flow hedge, net of tax	(3,536)					(3,536)
Issuance of common stock for exercise of options, restricted stock units and employee stock purchases (in shares)			822,000
Issuance of common stock for exercise of options, restricted stock units and employee stock purchases	57,930		$ 7	57,923
Issuance of mandatory convertible preferred stock (in shares)		770,000
Issuance of mandatory convertible preferred stock	$ 746,900	$ 8		$ 746,892
Purchase and cancellation of treasury stock (in shares)	(763,896)		(764,000)
Purchase and cancellation of treasury stock	$ (103,029)		$ (7)		(103,022)
Preferred stock dividend	(1,684)				(1,684)
Stock compensation expense	16,158			$ 16,158
Excess tax benefit of stock options exercised	15,483			15,483
Reduction to noncontrolling interests due to additional ownership	(5,236)						(5,236)
Ending Balance (in shares) at Sep. 30, 2015		770,000	84,942,000
Ending Balance at Sep. 30, 2015	$ 2,734,442	$ 8	$ 849	$ 1,125,667	$ 1,826,835	$ (237,246)	$ 18,329