Statement of Stockholders Equity Statement - USD ($) shares in Millions, $ in Millions	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]
Common stock, shares outstanding		177.4
Stockholders' Equity Attributable to Parent	$ 4,097.0	$ 44.4	$ (2,732.5)	$ 3,061.0	$ 3,732.9	$ (8.8)
Treasury Stock, Shares			51.0
Net income	284.9				284.9
StockIssuedDuringPeriodSharesShareBasedCompensationNetofRelatedTaxes(inshares)		0.7	0.2
StockIssuedDuringPeriodValueShareBasedCompensationNetofRelatedTaxes	(14.4)	$ 0.1	$ (19.6)	5.1
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	21.3			21.3
Treasury Stock, Shares, Acquired		(4.0)
Treasury Stock, Value, Acquired, Par Value Method	(284.0)	$ (1.0)	$ (284.0)	1.0
Stock Repurchased During Period, Shares			4.0
Dividends	(67.1)				(67.1)
Other Comprehensive Income (Loss), Net of Tax	0.6					0.6
Common stock, shares outstanding		170.5
Stockholders' Equity Attributable to Parent	$ 4,267.3	$ 42.6	$ (3,513.8)	3,251.9	4,494.6	(8.0)
Treasury Stock, Shares			61.1
Common stock, shares outstanding	170.1	170.1
Stockholders' Equity Attributable to Parent	$ 4,122.3	$ 42.5	$ (3,412.9)	3,188.0	4,312.6	(7.9)
Treasury Stock, Shares			60.1
Net income	257.1				257.1
StockIssuedDuringPeriodSharesShareBasedCompensationNetofRelatedTaxes(inshares)		1.1	0.3
StockIssuedDuringPeriodValueShareBasedCompensationNetofRelatedTaxes	8.2	$ 0.3	$ (26.7)	34.6
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	$ 29.1			29.1
Treasury Stock, Shares, Acquired	(0.7)	(0.7)
Treasury Stock, Value, Acquired, Par Value Method	$ (74.2)	$ (0.2)		$ 0.2
Stock Repurchased During Period, Shares			0.7
Dividends	(75.1)				$ (75.1)
Other Comprehensive Income (Loss), Net of Tax	$ 0.1					$ (0.1)
Common stock, shares outstanding	170.5
Stockholders' Equity Attributable to Parent	$ 4,267.3