Stock Compensation Plans (Restricted Stock, RSUs and Performance Shares Activity Rollforward) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Long-term incentive plan liability	$ 11.2	$ 23.2
Restricted Stock, Performance Shares, and Restricted Stock Units (RSUs) [Member]
Restricted Stock, RSUs and Performance Shares Activity [Roll Forward]
Outstanding, beginning of year	2,576	2,890	3,211
Granted	1,853	932	974
Vested	(546)	(1,090)	(1,019)
Forfeited	(909)	(156)	(276)
Outstanding, end of year	2,974	2,576	2,890
Vested, end of year	123	89	75
Outstanding, beginning of year, weighted-average per share grant date fair value	$ 18	$ 15	$ 11
Granted, weighted-average per share grant date fair value	17	22	19
Vested, weighted-average per share grant date fair value	20	10	10
Forfeited, weighted-average per share grant date fair value	12	19	15
Outstanding, end of year, weighted-average per share grant date fair value	19	18	15
Vested, end of year, weighted-average per share grant date fair value	$ 15	$ 14	$ 13