Equity - Shares Redeemed (Details) - $ / shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Equity, Class of Treasury Stock [Line Items]
Shares of common stock redeemed (shares)	3,297,240
Share Redemption Program
Equity, Class of Treasury Stock [Line Items]
Shares of common stock redeemed (shares)	0	217,088
Weighted average price per share (in dollars per share)	$ 0.00	$ 9.15