Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Reserves on receivables	$ 9	$ 8
Preferred stock - par value (in dollars per share)	$ 1	$ 1
Preferred stock - authorized shares (in shares)	36,000,000	36,000,000
Preferred stock - outstanding shares (in shares)	0	0
Common stock - par value (in dollars per share)	$ 0.1	$ 0.1
Common stock - authorized shares (in shares)	200,000,000	200,000,000
Common stock - issued shares (in shares)	146,513,000	146,167,000
Treasury stock, shares (in shares)	5,571,000	0