Condensed Consolidated Statements Of Shareholders' Equity (USD $) In Millions, except Share data	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balance at beginning of period at Dec. 31, 2011	$ 0.6	$ 1,467.5	$ 77.1		$ (415.0)	$ 1,130.2
Balance at beginning of period, shares at Dec. 31, 2011	58,424,691
Stock issuance	397,640
Share-based employee compensation		20.3				20.3
Net earnings			122.9			122.9
Dividends declared			(95.3)			(95.3)
Dividends declared in excess of retained earnings		(412.9)				(412.9)
Other comprehensive income (loss)					7.5	7.5
Balance at end of period at Sep. 30, 2012	0.6	1,074.9	104.7		(407.5)	772.7
Balance at end of period, shares at Sep. 30, 2012	58,822,331
Balance at beginning of period at Dec. 31, 2012	0.6	1,076.8	113.1		(471.4)	719.1
Balance at beginning of period, shares at Dec. 31, 2012	58,934,050					58,934,050
Stock issuance	274,587
Repurchase of common stock				(261.4)		(261.4)
Repurchase of common stock, shares	(5,057,382)
Repurchase of common stock, shares				5,057,382
Share-based employee compensation		14.7				14.7
Net earnings			83.3			83.3
Other comprehensive income (loss)					23.9	23.9
Balance at end of period at Sep. 30, 2013	$ 0.6	$ 1,091.5	$ 196.4	$ (261.4)	$ (447.5)	$ 579.6
Balance at end of period, shares at Sep. 30, 2013				5,057,382		5,057,382
Balance at end of period, shares at Sep. 30, 2013	54,151,255					54,151,255