Condensed Consolidated Statements of Equity (Parenthetical) - $ / shares	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Statement of Stockholders' Equity [Abstract]
Common dividends (in usd per share)	$ 0.185	$ 0.185	$ 0.17	$ 0.37	$ 0.34	$ 0.68