CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement of Comprehensive Income [Abstract]
Net income including non-controlling interests	$ 44,832	$ 64,252	$ 178,545	$ 203,622
Other comprehensive income (loss), net of tax:
Unrealized gain (loss) on derivatives designated and qualifying as cash flow hedges, net of tax of $(159) and $25 in the three and nine months ended September 30, 2014; $276 and $(55) in the three and nine months ended September 30, 2013	313	(734)	(284)	(147)
Defined benefit pension plan activity, net of tax of $1,974 and $5,235 in the three and nine months ended September 30, 2014; $2,050 and $8,232 in the three and nine months ended September 30, 2013	2,909	4,314	7,989	14,391
Currency translation adjustment	(49,550)	19,891	(49,778)	(15,209)
Other comprehensive (loss) income:	(46,328)	23,471	(42,073)	(965)
Comprehensive (loss) income	(1,496)	87,723	136,472	202,657
Comprehensive loss attributable to non-controlling interests	(797)	(1,678)	(164)	(1,769)
Comprehensive (loss) income attributable to shareholders	$ (699)	$ 89,401	$ 136,636	$ 204,426