Step Acquisition Business Combinations (Details) $ in Millions	9 Months Ended
	Sep. 30, 2015 USD ($)
Business Combinations [Abstract]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents	$ 3
Business Combination, Step Acquisition, Equity Interest in Acquiree, Fair Value	10
Business Combination, Step Acquisition, Equity Interest in Acquiree, Carrying Value	5
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other	4
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	29
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Long-term Debt	4
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt	14
Goodwill	10
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain	$ 5