Permanent and Temporary Equity (Redeemable OP Unitholder and Noncontrolling Interest) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($)
Increase (Decrease) in Temporary Equity [Roll Forward]
Balance as of December 31, 2015	$ 196,529
New issuances	14,851
Change in valuation	21,802
Distributions and other	(8,640)
Redemptions	(23,814)
Balance as of December 31, 2016	200,728
Redeemable Noncontrolling Interest
Increase (Decrease) in Temporary Equity [Roll Forward]
Balance as of December 31, 2015	7,983
New issuances	14,851
Change in valuation	717
Distributions and other	0
Redemptions	0
Balance as of December 31, 2016	23,551
Redeemable OP Unitholder Interest
Increase (Decrease) in Temporary Equity [Roll Forward]
Balance as of December 31, 2015	188,546
New issuances	0
Change in valuation	21,085
Distributions and other	(8,640)
Redemptions	(23,814)
Balance as of December 31, 2016	$ 177,177