Note 12. Stock-Based Compensation Incentive Equity Awards Activity - Summary of Option Activity (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
		Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Options, Weighted Average Exercise Price Roll Forward
Intrinsic value of options exercised		$ 5
Proceeds from exercise of stock options		5		$ 6	$ 5
Intrinsic value of outstanding options		$ 31
Weighted average remaining contractual life of outstanding options		6 years 7 months
Options
Options, Number of Shares Roll Forward
Outstanding at January 1, 2015		3,220,000.00
Granted		180,000.00
Exercised (a) (b)	[1],[2]	(210,000.00)
Forfeited/Expired		(40,000.00)
Outstanding at December 31, 2015 (c)		3,150,000.00	[3]	3,220,000.00
Options, Weighted Average Exercise Price Roll Forward
Outstanding at January 1, 2015		$ 30.02
Granted		46.45
Exercised (a) (b)	[1],[2]	22.09
Forfeited/Expired		32.48
Outstanding at December 31, 2015 (c)		$ 31.42	[3]	$ 30.02

[1] (a)The intrinsic value of options exercised during the year ended December 31, 2015 was $5 million.

[2] (b)Cash received from options exercised during the year ended December 31, 2015 was $5 million.

[3] (c)Options outstanding at December 31, 2015 had an intrinsic value of $31 million and have a weighted average remaining contractual life of 6.6 years.