Computation of Basic/Diluted Earnings Per Common Share (Details 2) (Details) - shares shares in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share [Abstract]
Common stock weighted-average shares, unvested restricted stock rights (in shares)	8	15
Shares not included in computation of diluted EPS due to unmet performance measures	3	4
Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted earnings per share (in shares)	1	2	5