Condensed Consolidating Financial Statements (Cash Flow) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities:
Net cash provided by operating activities	$ 426,592	$ 300,973
Cash flows from investing activities:
Capital expenditures	(44,505)	(48,810)
Payments for acquisition of a business, net of cash acquired	(354)	(6,545)
Purchases of investments	0	24,250
(Increase) decrease to investment in affiliates	0	0
Net cash used in investing activities	(44,859)	(79,605)
Cash flows from financing activities:
Proceeds from the issuance of long-term debt	982,500	0
Principal payments on long-term debt	(811,000)	(55,500)
Payment of promissory note	0	(40,000)
Premium and fees paid on extinguishment of debt	(40,953)	0
Payments for financing costs	(2,070)	0
Deemed repurchases of restricted stock/units	(10,821)	(14,454)
Purchase of treasury stock	(109,997)	0
Proceeds from stock option exercises	1,217	1,183
Excess tax benefits from share-based compensation arrangements	764	4,297
Principal payments on capital lease obligations	(3,182)	(2,392)
Distributions to noncontrolling interests	(9,010)	(3,154)
Contributions from noncontrolling interests	0	1,354
Net cash provided by (used in) financing activities	(2,552)	(108,666)
Net increase (decrease) in cash and cash equivalents from operations	379,181	112,702
Cash and cash equivalents at end of period	682,764	307,555
Effect of exchange rate changes on cash and cash equivalents	(12,738)	(6,514)
Consolidation, Eliminations [Member]
Cash flows from operating activities:
Net cash provided by operating activities	(476,390)	(503,441)
Cash flows from investing activities:
Capital expenditures	0	0
Payments for acquisition of a business, net of cash acquired	0	0
Purchases of investments		0
(Increase) decrease to investment in affiliates	323,341	434,097
Net cash used in investing activities	323,341	434,097
Cash flows from financing activities:
Proceeds from the issuance of long-term debt	0
Principal payments on long-term debt	0	0
Payment of promissory note
Premium and fees paid on extinguishment of debt	0
Payments for financing costs	0
Deemed repurchases of restricted stock/units	0	0
Purchase of treasury stock	0
Proceeds from stock option exercises	0	0
Excess tax benefits from share-based compensation arrangements	0	0
Principal payments on capital lease obligations	0	0
Distributions to noncontrolling interests	0	0
Contributions from noncontrolling interests		0
Net cash provided by (used in) financing activities	0	0
Net increase (decrease) in cash and cash equivalents from operations	(153,049)	(69,344)
Cash and cash equivalents at end of period	0	0
Effect of exchange rate changes on cash and cash equivalents	153,049	69,344
Parent Company [Member]
Cash flows from operating activities:
Net cash provided by operating activities	347,413	287,714
Cash flows from investing activities:
Capital expenditures	0	(9)
Payments for acquisition of a business, net of cash acquired	0	0
Purchases of investments		0
(Increase) decrease to investment in affiliates	(359,772)	(152,175)
Net cash used in investing activities	(359,772)	(152,184)
Cash flows from financing activities:
Proceeds from the issuance of long-term debt	982,500
Principal payments on long-term debt	(811,000)	(55,500)
Payment of promissory note		0
Premium and fees paid on extinguishment of debt	(40,953)
Payments for financing costs	(2,070)
Deemed repurchases of restricted stock/units	(10,821)	(14,454)
Purchase of treasury stock	(109,997)
Proceeds from stock option exercises	1,217	1,183
Excess tax benefits from share-based compensation arrangements	764	4,297
Principal payments on capital lease obligations	0	0
Distributions to noncontrolling interests	0	0
Contributions from noncontrolling interests		0
Net cash provided by (used in) financing activities	9,640	(64,474)
Net increase (decrease) in cash and cash equivalents from operations	(2,719)	71,056
Cash and cash equivalents at end of period	860	485
Effect of exchange rate changes on cash and cash equivalents	3,145	(72,152)
Guarantor Subsidiaries [Member]
Cash flows from operating activities:
Net cash provided by operating activities	504,454	171,707
Cash flows from investing activities:
Capital expenditures	(29,538)	(31,276)
Payments for acquisition of a business, net of cash acquired	0	0
Purchases of investments		0
(Increase) decrease to investment in affiliates	36,431	2,238
Net cash used in investing activities	6,893	(29,038)
Cash flows from financing activities:
Proceeds from the issuance of long-term debt	0
Principal payments on long-term debt	0	0
Payment of promissory note		0
Premium and fees paid on extinguishment of debt	0
Payments for financing costs	0
Deemed repurchases of restricted stock/units	0	0
Purchase of treasury stock	0
Proceeds from stock option exercises	0	0
Excess tax benefits from share-based compensation arrangements	0	0
Principal payments on capital lease obligations	(1,834)	(1,635)
Distributions to noncontrolling interests	0	0
Contributions from noncontrolling interests		0
Net cash provided by (used in) financing activities	(1,834)	(1,635)
Net increase (decrease) in cash and cash equivalents from operations	509,513	141,034
Cash and cash equivalents at end of period	504,724	155,366
Effect of exchange rate changes on cash and cash equivalents	(153,049)	(69,344)
Non-Guarantor Subsidiaries [Member]
Cash flows from operating activities:
Net cash provided by operating activities	51,115	344,993
Cash flows from investing activities:
Capital expenditures	(14,967)	(17,525)
Payments for acquisition of a business, net of cash acquired	(354)	(6,545)
Purchases of investments		24,250
(Increase) decrease to investment in affiliates	0	(284,160)
Net cash used in investing activities	(15,321)	(332,480)
Cash flows from financing activities:
Proceeds from the issuance of long-term debt	0
Principal payments on long-term debt	0	0
Payment of promissory note		(40,000)
Premium and fees paid on extinguishment of debt	0
Payments for financing costs	0
Deemed repurchases of restricted stock/units	0	0
Purchase of treasury stock	0
Proceeds from stock option exercises	0	0
Excess tax benefits from share-based compensation arrangements	0	0
Principal payments on capital lease obligations	(1,348)	(757)
Distributions to noncontrolling interests	(9,010)	(3,154)
Contributions from noncontrolling interests		1,354
Net cash provided by (used in) financing activities	(10,358)	(42,557)
Net increase (decrease) in cash and cash equivalents from operations	25,436	(30,044)
Cash and cash equivalents at end of period	177,180	151,704
Effect of exchange rate changes on cash and cash equivalents	$ (15,883)	$ 65,638