Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Earnings Per Share [Abstract]
Net income	$ 67	$ 24
Effect of dilutive securities - Deferred compensation program for non-employee directors	0	0
Income available to shareholders	$ 67	$ 24
Average common shares	145,819,026	145,381,269
Dilutive RSUs, MSUs, performance shares and stock options	1,200,000	1,600,000
Deferred shares associated with a deferred compensation program for non-employee directors	0	200,000
Average diluted common shares	146,986,392	147,176,197
Earnings per average common share	$ 0.46	$ 0.16
Earnings per average diluted common share	$ 0.46	$ 0.16