Equity - Shares and Units and Dividends (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Class of Stock [Line Items]
OP Unit, redemption for cash, term	1 year
Percentage of dividends on common stock received until performance criteria met for LTIP units	10.00%
Percentage of dividends on common stock received after performance criteria met for LTIP units	90.00%
Percentage of dividends on common stock received in periods after performance criteria met for LTIP units	100.00%
Net income attributable to common stockholders	$ 9,985	$ 7,428
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	$ 17,796	14,286
Shares and Units [Abstract]
OP units outstanding (shares)	300,367,915
OP units owned by the Company (shares)	157,784,591
OP units owned by the Company, percent	52.50%
OP units not owned by the Company (shares)	142,583,324
OP units not owned by the Company, percent	47.50%
Dividends and Distributions [Abstract]
Dividends paid to common shareholders	$ 16,500	10,300
Distributions paid to OP unitholders	14,900	12,600
Private perpetual preferred unit distributions	234	234
Additional Paid-In Capital
Class of Stock [Line Items]
Increase in additional paid-in capital for the conversion of OP Units into common stock	$ 7,811	$ 6,858