Consolidated Statement Of Changes In Equity (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Stockholders' Equity [Abstract]
Dividends (in usd per share)	$ 1.95	$ 2.45	$ 3.08
Underwriting Discount	$ 0.0	$ 0.0	$ 3.0