CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Millions	Total		Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Retained Earnings	Treasury Stock
Balance at Beginning of Year at Dec. 31, 2012			$ 36.0	$ 2,607.7	$ 628.0	$ 7,363.5	$ (2,030.7)
Increase (Decrease) in Stockholders' Equity
Common Stock Activity			0.1	26.4
Retirement of Treasury Stock			0.0	0.0		0.0
Other Comprehensive Loss	$ (373.0)				(373.0)
Net Income	847.0					847.0
Dividends to Stockholders (per common share: $0.70; $0.62; $0.55)						(146.5)
Purchases of Treasury Stock	(318.6)	[1]					(318.6)
Retirement of Stock from Treasury							0.0
Balance at End of Year at Dec. 31, 2013	8,639.9		36.1	2,634.1	255.0	8,064.0	(2,349.3)
Increase (Decrease) in Stockholders' Equity
Common Stock Activity			0.1	28.4
Retirement of Treasury Stock	(1,451.7)		(6.0)	(441.3)		(1,004.4)
Other Comprehensive Loss	(88.6)				(88.6)
Net Income	402.1					402.1
Dividends to Stockholders (per common share: $0.70; $0.62; $0.55)						(159.4)
Purchases of Treasury Stock	(300.6)	[1]					(300.6)
Retirement of Stock from Treasury							1,451.7
Balance at End of Year at Dec. 31, 2014	8,521.9		30.2	2,221.2	166.4	7,302.3	(1,198.2)
Increase (Decrease) in Stockholders' Equity
Common Stock Activity			0.1	26.0
Retirement of Treasury Stock			0.0	0.0		0.0
Other Comprehensive Loss	(150.3)				(150.3)
Net Income	867.1					867.1
Dividends to Stockholders (per common share: $0.70; $0.62; $0.55)						(174.2)
Purchases of Treasury Stock	(426.7)	[1]					(426.7)
Retirement of Stock from Treasury							0.0
Balance at End of Year at Dec. 31, 2015	$ 8,663.9		$ 30.3	$ 2,247.2	$ 16.1	$ 7,995.2	$ (1,624.9)

[1] Includes commissions of $0.3 million, $0.1 million, and $0.2 million for the years ended December 31, 2015, 2014, and 2013, respectively.