Equity - Change in Net Income Attributable to Common Shareholders (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Class of Stock [Line Items]
Net income attributable to common stockholders	$ 16,584	$ 11,089	$ 26,569	$ 18,517
Increase in additional paid-in capital for the conversion of OP Units into common stock			0
Change from net income attributable to common stockholders and transfers from non-controlling interests	17,907	19,432	35,703	33,718
Additional Paid-In Capital
Class of Stock [Line Items]
Increase in additional paid-in capital for the conversion of OP Units into common stock	$ 1,323	$ 8,343	$ 9,134	$ 15,201