Noncontrolling Interests In Operating Partnership - Schedule of OP Unit Activity (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Noncontrolling Interest [Abstract]
OP Units redeemed for common stock (in units)	0	23,850	787,850
OP Units redeemed for cash (in units)	33,896	6,760	0
Cash paid for OP Units redeemed	$ 2,510	$ 506	$ 0
OP Units issued in conjunction with acquisitions (in units)	90,228	93,569	2,043,613
Value of OP Units issued in conjunction with acquisitions	$ 7,618	$ 7,247	$ 142,399