Consolidated Statements of Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Dividends per share
Dividends on common stock, per common share	$ 0.60	$ 0.30	$ 0.30
Repurchases of shares of common stock (in shares)	9,188,589	446,464
Series A Preferred Stock
Dividends per share
Dividends on preferred stock		7.50%	7.50%
Series B Preferred Stock
Dividends per share
Dividends on preferred stock	6.45%	6.45%	6.45%
Series C Preferred Stock
Dividends per share
Dividends on preferred stock	5.70%	5.70%