Condensed Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Net income	$ 148,400,000	$ 90,700,000
Other comprehensive income (loss):
Change in derivative instruments designated as cash flow hedges, net of tax	400,000	3,200,000
Foreign currency translation adjustments	1,000,000	(2,100,000)
Benefit plan adjustments, net of tax	1,600,000	2,200,000
Other comprehensive income (loss)	3,000,000	3,300,000
Comprehensive income	$ 151,400,000	$ 94,000,000