CONSOLIDATED STATEMENTS OF COMPREHENSIVE EARNINGS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
NET INCOME	$ 100,711	$ 90,002	$ 83,984
Other comprehensive earnings (loss), net of tax
Foreign currency translation adjustments	(708)	826	2,645
Pension and other postretirement benefit plans	(14,892)	(1,189)	(14)
Other comprehensive (loss) earnings	(15,600)	(363)	2,631
Comprehensive earnings	$ 85,111	$ 89,639	$ 86,615