Earnings per Common Share - Table 2 (Details) - shares shares in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share [Abstract]
Basic weighted average common shares outstanding	89.4	86.8	88.1
Convertible perpetual preferred stock	1.0	3.2	10.5
Convertible senior subordinated notes	8.3	8.2	1.0
Restricted stock awards, dilutive stock options, and restricted stock units	2.3	2.5	2.5
Diluted weighted average common shares outstanding	101.0	100.7	102.1