Divestitures 2 (Details) $ in Millions	3 Months Ended
	Mar. 31, 2016 USD ($)
ERwin
Additional Disclosures by Disposal Groups, Including Discontinued Operations
Proceeds from sale of discontinued component	$ 50
Gain (loss) on disposal of discontinued component, net of tax	4
Tax expense related to gain on disposal of discontinued component	24
Goodwill written off related to sale of discontinued component	36
Prior Period Divestiture
Additional Disclosures by Disposal Groups, Including Discontinued Operations
Gain (loss) on disposal of discontinued component, net of tax	$ (2)