Accumulated Other Comprehensive Loss (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income tax expense	$ 15,586		$ 13,054	$ 23,361		$ 64,117
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	(274,256)			(183,347)
Other comprehensive loss before reclassifications, net of tax	(24,403)			(116,432)
Amounts reclassified from accumulated other comprehensive loss, net of tax	644			1,764
Net current-period other comprehensive income (loss)	(23,759)			(114,668)
Balance at end of period	(298,015)			(298,015)
Unrealized Losses on Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income tax expense	100			100
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	(1,182)	[1]		(4,358)	[2]
Other comprehensive loss before reclassifications, net of tax	(1,289)	[1]		1,167	[2]
Amounts reclassified from accumulated other comprehensive loss, net of tax	445	[1]		1,165	[2]
Net current-period other comprehensive income (loss)	(844)	[1]		2,332	[2]
Balance at end of period	(2,026)	[1],[2]		(2,026)	[1],[2]
Treasury Lock [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	(3,427)			(3,827)
Other comprehensive loss before reclassifications, net of tax	0			0
Amounts reclassified from accumulated other comprehensive loss, net of tax	199			599
Net current-period other comprehensive income (loss)	199			599
Balance at end of period	(3,228)			(3,228)
Foreign Currency Items [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	(269,647)			(175,162)
Other comprehensive loss before reclassifications, net of tax	(23,114)			(117,599)
Amounts reclassified from accumulated other comprehensive loss, net of tax	0			0
Net current-period other comprehensive income (loss)	(23,114)			(117,599)
Balance at end of period	$ (292,761)			$ (292,761)

[1] Losses on cash flow hedges have been reclassified into interest expense in the accompanying condensed consolidated statements of operations. The tax effect of less than $0.1 million is included in income tax expense for the three months ended September 30, 2013.

[2] Losses on cash flow hedges have been reclassified into interest expense in the accompanying condensed consolidated statements of operations. The tax effect of $0.1 million is included in income tax expense for the nine months ended September 30, 2013.