Equity - Change in Net Income Attributable to Common Shareholders (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Class of Stock [Line Items]
Net income attributable to common stockholders	$ 11,087	$ 16,651	$ 16,764	$ 26,419
Increase in additional paid-in capital for the conversion of OP Units into common stock	0	0	0	0
Change from net income attributable to common stockholders and transfers from non-controlling interests	16,681	32,329	25,629	52,259
Additional Paid-In Capital
Class of Stock [Line Items]
Increase in additional paid-in capital for the conversion of OP Units into common stock	$ 5,594	$ 15,678	$ 8,865	$ 25,840