Condensed Consolidating Financial Statements (Cash Flow) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash flows from operating activities:
Net cash provided by operating activities	$ 190,241	$ 177,451
Cash flows from investing activities:
Capital expenditures	(33,124)	(18,755)
Payments for acquisitions, net of cash acquired	(6,545)	(993,210)
Purchases of investments	(24,250)	0
(Increase) Decrease in Consolidated Subsidiaries	0	0
Proceeds from insurance settlements	0	654
Net cash used in investing activities	(63,919)	(1,011,311)
Cash flows from financing activities:
Proceeds from the issuance of long-term debt	0	600,000
Payments for financing costs	0	9,266
Principal payments on long-term debt	(37,000)	0
Payment of Promissory Note	(40,000)	0
Deemed repurchases of restricted stock/units	(14,320)	(17,804)
Proceeds from stock option exercises	1,031	925
Excess tax benefits from share-based compensation arrangements	4,038	4,708
Principal payments on capital lease obligations	(1,449)	(1,312)
Distributions to noncontrolling member	(3,154)	0
Long-term intercompany debt		0
Cash contributions from member		0
Contributions from noncontrolling member	1,373	835
Net cash (used in) provided by financing activities	(89,481)	578,086
Net increase (decrease) in cash and cash equivalents from continuing operations	36,841	(255,774)
Cash flows from discontinued operations
Net cash used in operating activities	0	(2,719)
Net decrease in cash and cash equivalents from discontinued operations	0	(2,719)
Effect of exchange rate changes on cash and cash equivalents	2,852	20,534
Cash and cash equivalents at beginning of period	201,367	521,951
Cash and cash equivalents at end of period	241,060	283,992
Consolidation, Eliminations [Member]
Cash flows from operating activities:
Net cash provided by operating activities	(411,248)	(155,613)
Cash flows from investing activities:
Capital expenditures	0	0
Payments for acquisitions, net of cash acquired	0	0
Purchases of investments	0
(Increase) Decrease in Consolidated Subsidiaries	347,025	170,987
Proceeds from insurance settlements		0
Net cash used in investing activities	347,025	170,987
Cash flows from financing activities:
Proceeds from the issuance of long-term debt		0
Payments for financing costs		0
Principal payments on long-term debt	0
Payment of Promissory Note	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 member	0
Long-term intercompany debt		0
Cash contributions from member		0
Contributions from noncontrolling member	0	0
Net cash (used in) provided by financing activities	0	0
Net increase (decrease) in cash and cash equivalents from continuing operations	(64,223)	15,374
Cash flows from discontinued operations
Net cash used in operating activities	0	0
Net decrease in cash and cash equivalents from discontinued operations	0	0
Effect of exchange rate changes on cash and cash equivalents	64,223	(15,374)
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	238,455	153,255
Cash flows from investing activities:
Capital expenditures	(3)	(1,371)
Payments for acquisitions, net of cash acquired	0	0
Purchases of investments	0
(Increase) Decrease in Consolidated Subsidiaries	(134,957)	(38,589)
Proceeds from insurance settlements		0
Net cash used in investing activities	(134,960)	(39,960)
Cash flows from financing activities:
Proceeds from the issuance of long-term debt		600,000
Payments for financing costs		9,266
Principal payments on long-term debt	(37,000)
Payment of Promissory Note	0
Deemed repurchases of restricted stock/units	(14,320)	(17,804)
Proceeds from stock option exercises	1,031	925
Excess tax benefits from share-based compensation arrangements	4,038	4,708
Principal payments on capital lease obligations	0	0
Distributions to noncontrolling member	0
Long-term intercompany debt		(706,190)
Cash contributions from member		0
Contributions from noncontrolling member	0	0
Net cash (used in) provided by financing activities	(46,251)	(127,627)
Net increase (decrease) in cash and cash equivalents from continuing operations	57,244	(14,332)
Cash flows from discontinued operations
Net cash used in operating activities	0	0
Net decrease in cash and cash equivalents from discontinued operations	0	0
Effect of exchange rate changes on cash and cash equivalents	(57,931)	15,374
Cash and cash equivalents at beginning of period	1,581	942
Cash and cash equivalents at end of period	894	1,984
Guarantor Subsidiaries [Member]
Cash flows from operating activities:
Net cash provided by operating activities	169	141,858
Cash flows from investing activities:
Capital expenditures	(22,875)	(13,086)
Payments for acquisitions, net of cash acquired	0	(1,009,286)
Purchases of investments	(369)
(Increase) Decrease in Consolidated Subsidiaries	127,384	(161,166)
Proceeds from insurance settlements		654
Net cash used in investing activities	104,140	(1,182,884)
Cash flows from financing activities:
Proceeds from the issuance of long-term debt		0
Payments for financing costs		0
Principal payments on long-term debt	0
Payment of Promissory Note	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	(1,097)	(865)
Distributions to noncontrolling member	0
Long-term intercompany debt		706,190
Cash contributions from member		(5,100)
Contributions from noncontrolling member	0	0
Net cash (used in) provided by financing activities	(1,097)	700,225
Net increase (decrease) in cash and cash equivalents from continuing operations	103,212	(340,801)
Cash flows from discontinued operations
Net cash used in operating activities	0	0
Net decrease in cash and cash equivalents from discontinued operations	0	0
Effect of exchange rate changes on cash and cash equivalents	(64,223)	15,374
Cash and cash equivalents at beginning of period	83,676	519,392
Cash and cash equivalents at end of period	122,665	193,965
Non-Guarantor Subsidiaries [Member]
Cash flows from operating activities:
Net cash provided by operating activities	362,865	37,951
Cash flows from investing activities:
Capital expenditures	(10,246)	(4,298)
Payments for acquisitions, net of cash acquired	(6,545)	16,076
Purchases of investments	(23,881)
(Increase) Decrease in Consolidated Subsidiaries	(339,452)	28,768
Proceeds from insurance settlements		0
Net cash used in investing activities	(380,124)	40,546
Cash flows from financing activities:
Proceeds from the issuance of long-term debt		0
Payments for financing costs		0
Principal payments on long-term debt	0
Payment of Promissory Note	(40,000)
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	(352)	(447)
Distributions to noncontrolling member	(3,154)
Long-term intercompany debt		0
Cash contributions from member		5,100
Contributions from noncontrolling member	1,373	835
Net cash (used in) provided by financing activities	(42,133)	5,488
Net increase (decrease) in cash and cash equivalents from continuing operations	(59,392)	83,985
Cash flows from discontinued operations
Net cash used in operating activities	0	(2,719)
Net decrease in cash and cash equivalents from discontinued operations	0	(2,719)
Effect of exchange rate changes on cash and cash equivalents	60,783	5,160
Cash and cash equivalents at beginning of period	116,110	1,617
Cash and cash equivalents at end of period	$ 117,501	$ 88,043