Condensed 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	$ 83,276	$ 77,175	$ 158,755	$ 162,137
Other comprehensive income (loss), net of tax:
Changes in net prior service credit and actuarial losses	(225)	1,958	(769)	5,717
Change in fair value of derivatives	1,310	152	2,648	3,013
Foreign currency translation	(34,688)	11,553	(41,776)	(5,036)
Other comprehensive (loss) income	(33,603)	13,663	(39,897)	3,694
Comprehensive income	$ 49,673	$ 90,838	$ 118,858	$ 165,831