Consolidated Statements of Equity (Parenthetical) - $ / shares	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Statement of Stockholders' Equity [Abstract]
Special cash dividends paid to certain common stockholders (in usd per share)	$ 2.26
Common dividends (in usd per share)	0.46875	$ 0.65625
Dividends to holders of Series A Preferred Stock (in usd per share)	$ 1.03125