Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Millions	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Beginning balance at Dec. 31, 2013		$ 0.0		$ 1,035.7	$ 7,134.8	$ (244.3)	$ (422.8)
Issuance of Preferred Stock, Series C		388.5
Stock Options and Awards				(55.0)			177.0
Stock Options and Awards — Amortization				60.4
Stock Options and Awards — Tax Benefits				14.4
Net Income	$ 567.8				567.8
Dividends Declared — Common Stock					(233.2)
Dividends Declared — Preferred Stock					0.0
Net Unrealized Gains (Losses) on Securities Available for Sale	32.3					32.3
Net Unrealized Gains (Losses) on Cash Flow Hedges	(6.4)					(6.4)
Foreign Currency Translation Adjustments	(10.5)					(10.5)
Pension and Other Postretirement Benefit Adjustments	10.5					10.5
Stock Purchased							(315.2)
Ending balance at Sep. 30, 2014	8,542.6	388.5	$ 408.6	1,055.5	7,469.4	(218.4)	(561.0)
Beginning balance at Dec. 31, 2014	8,448.9	388.5		1,050.9	7,625.4	(319.7)	(704.8)
Issuance of Preferred Stock, Series C		0.0
Stock Options and Awards				(69.7)			157.9
Stock Options and Awards — Amortization				59.9
Stock Options and Awards — Tax Benefits				17.6
Net Income	734.5				734.5
Dividends Declared — Common Stock					(248.7)
Dividends Declared — Preferred Stock					(17.5)
Net Unrealized Gains (Losses) on Securities Available for Sale	24.7					24.7
Net Unrealized Gains (Losses) on Cash Flow Hedges	5.3					5.3
Foreign Currency Translation Adjustments	(2.4)					(2.4)
Pension and Other Postretirement Benefit Adjustments	18.4					18.4
Stock Purchased	(344.4)						(344.4)
Ending balance at Sep. 30, 2015	$ 8,784.5	$ 388.5	$ 408.6	$ 1,058.7	$ 8,093.7	$ (273.7)	$ (891.3)