Investments in Affiliates Significant Affiliates Financial Statements (Unaudited) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Equity Method Investments and Joint Ventures [Abstract]
Current assets	$ 222	$ 195
Non-current assets	108	96
Total assets	330	291
Current liabilities	114	124
Non-current liabilities	4	4
Shareholders' equity	212	163
Total liabilities and shareholders' equity	330	291
Net sales	570	521	$ 440
Gross profit	111	105	84
Net income	$ 66	$ 77	$ 39