Acquisitions (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Jun. 30, 2015	Sep. 30, 2015	Sep. 30, 2014
Business Acquisition [Line Items]
Cost of acquisition paid in cash		$ 83	$ 3
Series of Individually Immaterial Business Acquisitions [Member]
Business Acquisition [Line Items]
Total cost of acquisitions		90
Cost of acquisition paid in cash		83
Business Acquisition, Purchase Price Allocation, Working Capital		(9)
Business Acquisition, Purchase Price Allocation, Property, Plant and Equipment		67
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets		2
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		123
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt		17
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities		20
NSS and Minmetal [Member]
Business Acquisition [Line Items]
Business Combination, Step Acquisition, Equity Interest in Acquiree, Fair Value		$ 63
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain	$ 27