Earnings per Common Share - Table 3 (Details) - $ / shares shares in Millions	1 Months Ended	12 Months Ended
	Jan. 16, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2012	Sep. 30, 2009
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Outstanding, Beginning Balance		10.0
Warrants expired	(0.1)
Stock Warrants Issued, Exercise Price	$ 32.16		$ 32.50	$ 32.50	$ 41.40
Class of Warrant or Right, Outstanding, Ending Balance	0.0
Cashless exercise [Member]
Class of Warrant or Right [Line Items]
Warrants exercised	(1.8)	(4.8)
Stock Warrants Issued, Exercise Price	$ 32.16	$ 32.50
Cash exercise [Member]
Class of Warrant or Right [Line Items]
Warrants exercised	(1.0)	(2.3)
Stock Warrants Issued, Exercise Price	$ 32.16	$ 32.50