CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement of Comprehensive Income [Abstract]
Net earnings	$ 177,015	$ 222,398	$ 221,474
Other comprehensive income (loss), net of tax:
Pension plans	2,961	745	(1,113)
Fair value adjustment on interest rate swap contracts	1,660	0	0
Foreign currency translation adjustments	11,838	20,790	(12,533)
Total other comprehensive income (loss)	16,459	21,535	(13,646)
Comprehensive income	$ 193,474	$ 243,933	$ 207,828