Note 9. Employee Benefit Plans Fair Value of Plan Assets by Category (Details) (Defined Benefit Pension Plan, USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 114	$ 113	$ 104
Quoted Price in Active Market for Identical Assets (Level I)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1	3
Significant Other Observable Inputs (Level II)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	113	110
Significant Unobservable Inputs (Level III)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1	3
Cash and cash equivalents | Quoted Price in Active Market for Identical Assets (Level I)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1	3
Cash and cash equivalents | Significant Other Observable Inputs (Level II)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and cash equivalents | Significant Unobservable Inputs (Level III)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. large-cap funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	33	33
U.S. large-cap funds | Quoted Price in Active Market for Identical Assets (Level I)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. large-cap funds | Significant Other Observable Inputs (Level II)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	33	33
U.S. large-cap funds | Significant Unobservable Inputs (Level III)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. small-cap funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9	9
U.S. small-cap funds | Quoted Price in Active Market for Identical Assets (Level I)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. small-cap funds | Significant Other Observable Inputs (Level II)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9	9
U.S. small-cap funds | Significant Unobservable Inputs (Level III)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
International funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	22	23
International funds | Quoted Price in Active Market for Identical Assets (Level I)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
International funds | Significant Other Observable Inputs (Level II)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	22	23
International funds | Significant Unobservable Inputs (Level III)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Real estate fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7	5
Real estate fund | Quoted Price in Active Market for Identical Assets (Level I)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Real estate fund | Significant Other Observable Inputs (Level II)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7	5
Real estate fund | Significant Unobservable Inputs (Level III)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Bond funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	42	40
Bond funds | Quoted Price in Active Market for Identical Assets (Level I)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Bond funds | Significant Other Observable Inputs (Level II)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	42	40
Bond funds | Significant Unobservable Inputs (Level III)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ 0