CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (UNAUDITED) - 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, 2014		$ 30.2	$ 2,221.2	$ 166.4	$ 7,302.3	$ (1,198.2)
Increase (Decrease) in Stockholders' Equity
Common Stock Activity			9.5
Other Comprehensive Income	$ 94.0			94.0
Net Income	212.9				212.9
Dividends to Stockholders (per common share: $0.185; $0.165)					(42.3)
Purchases of Treasury Stock	(108.1)					(108.1)
Balance at End of Period at Mar. 31, 2015	8,687.9	30.2	2,230.7	260.4	7,472.9	(1,306.3)
Balance at Beginning of Year at Dec. 31, 2015	8,663.9	30.3	2,247.2	16.1	7,995.2	(1,624.9)
Increase (Decrease) in Stockholders' Equity
Common Stock Activity			6.4
Other Comprehensive Income	184.6			184.6
Net Income	210.6				210.6
Dividends to Stockholders (per common share: $0.185; $0.165)					(45.2)
Purchases of Treasury Stock	(100.0)					(100.0)
Balance at End of Period at Mar. 31, 2016	$ 8,920.3	$ 30.3	$ 2,253.6	$ 200.7	$ 8,160.6	$ (1,724.9)