CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Noncontrolling Interests
Beginning Balance at Dec. 31, 2015	$ 2,747,838	$ 8	$ 849	$ 1,143,020	$ 1,868,645	$ (282,631)	$ 17,947
Beginning Balance (in shares) at Dec. 31, 2015		770	84,853
Net (loss) income	207,899				206,359		1,540
Currency translation adjustment	(86,575)					(86,340)	(235)
Change in qualifying cash flow hedge, net of tax	1,328					1,328
Issuance of common stock for stock-based compensation awards and employee stock purchases	44,769		$ 6	44,763
Issuance of common stock for stock-based compensation awards and employee stock purchases (in shares)			661
Purchase and cancellation of treasury stock	(40,814)		$ (3)		(40,811)
Purchase and cancellation of treasury stock (in shares)			(361)
Purchase and cancellation of convertible preferred stock	(30,910)	$ (1)		(42,194)	11,285
Purchase and cancellation of convertible preferred stock (in shares)		(44)
Preferred stock dividend	(39,414)				(39,414)
Stock-based compensation expense	20,455			20,455
Reduction to noncontrolling interests due to additional ownership	(8,190)			413			(8,603)
Ending Balance at Dec. 31, 2016	2,816,386	$ 7	$ 852	1,166,457	2,006,064	(367,643)	10,649
Ending Balance (in shares) at Dec. 31, 2016		726	85,153
Net (loss) income	(46,566)				(46,815)		249
Currency translation adjustment	80,772					79,889	883
Change in qualifying cash flow hedge, net of tax	1,061					1,061
Issuance of common stock for stock-based compensation awards and employee stock purchases	8,853		$ 2	8,851
Issuance of common stock for stock-based compensation awards and employee stock purchases (in shares)			199
Purchase and cancellation of convertible preferred stock	(30,832)			(45,222)	14,390
Purchase and cancellation of convertible preferred stock (in shares)		(46)
Preferred stock dividend	(27,506)				(27,506)
Stock-based compensation expense	17,262			17,262
Reduction to noncontrolling interests due to additional ownership	(709)			(266)			(443)
Ending Balance at Sep. 30, 2017	$ 2,818,721	$ 7	$ 854	$ 1,147,082	$ 1,946,133	$ (286,693)	$ 11,338
Ending Balance (in shares) at Sep. 30, 2017		680	85,352