Accumulated Other Comprehensive Income (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accumulated other comprehensive income, beginning balance	$ 6,089,000	$ 47,271,000
Other comprehensive (loss)/income, before reclassifications	(76,922,000)	(38,727,000)
Amounts reclassified from accumulated other comprehensive income, net of tax	(1,419,000)	(2,455,000)
Current period change	(78,341,000)	(41,182,000)	9,376,000
Accumulated other comprehensive income, ending balance	(72,252,000)	6,089,000	47,271,000
Accumulated Translation Adjustment [Member]
Accumulated other comprehensive income, beginning balance	(14,687,000)	47,845,000
Other comprehensive (loss)/income, before reclassifications	(56,059,000)	(62,532,000)
Amounts reclassified from accumulated other comprehensive income, net of tax	0	0
Current period change	(56,059,000)	(62,532,000)
Accumulated other comprehensive income, ending balance	(70,746,000)	(14,687,000)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated other comprehensive income, beginning balance	214,000	(148,000)
Other comprehensive (loss)/income, before reclassifications	1,191,000	362,000
Amounts reclassified from accumulated other comprehensive income, net of tax	0	0
Current period change	1,191,000	362,000
Accumulated other comprehensive income, ending balance	1,405,000	214,000
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated other comprehensive income, beginning balance	20,562,000	(426,000)
Other comprehensive (loss)/income, before reclassifications	(22,054,000)	23,443,000
Amounts reclassified from accumulated other comprehensive income, net of tax	(1,419,000)	(2,455,000)
Current period change	(23,473,000)	20,988,000
Accumulated other comprehensive income, ending balance	(2,911,000)	20,562,000
Tax benefit on amounts reclassified from AOCI	$ 1,637,000	$ 946,000