Condensed Consolidating Financial Statements (Cash Flow) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash flows from operating activities:
Net cash provided by operating activities	$ 167,384	$ 80,195
Cash flows from investing activities:
Capital expenditures	(12,387)	(18,248)
Payments for acquisition of a business, net of cash acquired	0	(6,581)
Purchases of investments	0	(25,210)
(Increase) decrease to investment in affiliates	0	0
Net cash used in investing activities	(12,387)	(50,039)
Cash flows from financing activities:
Proceeds from the issuance of long-term debt	982,500	0
Principal payments on long-term debt	(691,449)	(18,500)
Premium and fees paid on extinguishment of debt	39,179	0
Payments for financing costs	(2,070)	0
Deemed repurchases of restricted stock/units	(10,413)	(12,848)
Proceeds from stock option exercises	1,200	130
Excess tax benefits from share-based compensation arrangements	852	3,672
Principal payments on capital lease obligations	(1,086)	(1,420)
Distributions to noncontrolling interest	(8,968)	0
Net cash provided by (used in) financing activities	231,387	(28,966)
Net increase in cash and cash equivalents from operations	386,384	1,190
Effect of exchange rate changes on cash and cash equivalents	95	(8,250)
Cash and cash equivalents at beginning of period	316,321	201,367
Cash and cash equivalents at end of period	702,800	194,307
Consolidation, Eliminations [Member]
Cash flows from operating activities:
Net cash provided by operating activities	(249,552)	(280,489)
Cash flows from investing activities:
Capital expenditures	0	0
Payments for acquisition of a business, net of cash acquired		0
Purchases of investments		0
(Increase) decrease to investment in affiliates	246,257	208,797
Net cash used in investing activities	246,257	208,797
Cash flows from financing activities:
Proceeds from the issuance of long-term debt	0
Principal payments on long-term debt	0	0
Premium and fees paid on extinguishment of debt	0
Payments for financing costs	0
Deemed repurchases of restricted stock/units	0	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 interest	0
Net cash provided by (used in) financing activities	0	0
Net increase in cash and cash equivalents from operations	(3,295)	(71,692)
Effect of exchange rate changes on cash and cash equivalents	3,295	71,692
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	0	0
Parent Company [Member]
Cash flows from operating activities:
Net cash provided by operating activities	204,100	223,495
Cash flows from investing activities:
Capital expenditures	2	(9)
Payments for acquisition of a business, net of cash acquired		0
Purchases of investments		0
(Increase) decrease to investment in affiliates	(160,665)	(122,915)
Net cash used in investing activities	(160,663)	(122,924)
Cash flows from financing activities:
Proceeds from the issuance of long-term debt	982,500
Principal payments on long-term debt	(691,449)	(18,500)
Premium and fees paid on extinguishment of debt	39,179
Payments for financing costs	(2,070)
Deemed repurchases of restricted stock/units	(10,413)	(12,848)
Proceeds from stock option exercises	1,200	130
Excess tax benefits from share-based compensation arrangements	852	3,672
Principal payments on capital lease obligations	0	0
Distributions to noncontrolling interest	0
Net cash provided by (used in) financing activities	241,441	(27,546)
Net increase in cash and cash equivalents from operations	284,878	73,025
Effect of exchange rate changes on cash and cash equivalents	(5,844)	(73,735)
Cash and cash equivalents at beginning of period	434	1,581
Cash and cash equivalents at end of period	279,468	871
Guarantor Subsidiaries [Member]
Cash flows from operating activities:
Net cash provided by operating activities	193,453	111,816
Cash flows from investing activities:
Capital expenditures	(8,151)	(13,416)
Payments for acquisition of a business, net of cash acquired		0
Purchases of investments		(82)
(Increase) decrease to investment in affiliates	(72,411)	(14,892)
Net cash used in investing activities	(80,562)	(28,390)
Cash flows from financing activities:
Proceeds from the issuance of long-term debt	0
Principal payments on long-term debt	0	0
Premium and fees paid on extinguishment of debt	0
Payments for financing costs	0
Deemed repurchases of restricted stock/units	0	0
Proceeds from stock option exercises	0	0
Excess tax benefits from share-based compensation arrangements	0	0
Principal payments on capital lease obligations	(597)	(542)
Distributions to noncontrolling interest	0
Net cash provided by (used in) financing activities	(597)	(542)
Net increase in cash and cash equivalents from operations	112,294	82,884
Effect of exchange rate changes on cash and cash equivalents	(3,295)	(71,692)
Cash and cash equivalents at beginning of period	148,260	83,676
Cash and cash equivalents at end of period	257,259	94,868
Non-Guarantor Subsidiaries [Member]
Cash flows from operating activities:
Net cash provided by operating activities	19,383	25,373
Cash flows from investing activities:
Capital expenditures	(4,238)	(4,823)
Payments for acquisition of a business, net of cash acquired		(6,581)
Purchases of investments		(25,128)
(Increase) decrease to investment in affiliates	(13,181)	(70,990)
Net cash used in investing activities	(17,419)	(107,522)
Cash flows from financing activities:
Proceeds from the issuance of long-term debt	0
Principal payments on long-term debt	0	0
Premium and fees paid on extinguishment of debt	0
Payments for financing costs	0
Deemed repurchases of restricted stock/units	0	0
Proceeds from stock option exercises	0	0
Excess tax benefits from share-based compensation arrangements	0	0
Principal payments on capital lease obligations	(489)	(878)
Distributions to noncontrolling interest	(8,968)
Net cash provided by (used in) financing activities	(9,457)	(878)
Net increase in cash and cash equivalents from operations	(7,493)	(83,027)
Effect of exchange rate changes on cash and cash equivalents	5,939	65,485
Cash and cash equivalents at beginning of period	167,627	116,110
Cash and cash equivalents at end of period	$ 166,073	$ 98,568