Noncontrolling Interest Represented By Preferred Operating Partnership Units (Details) - USD ($) $ / shares in Units, $ in Thousands				1 Months Ended			3 Months Ended								12 Months Ended
	Dec. 01, 2018	Apr. 18, 2017	Jun. 25, 2007	Dec. 31, 2014	Oct. 31, 2014	Jun. 30, 2007	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Noncontrolling Interest [Line Items]
Loan to holders of preferred OP units							$ 108,644				$ 120,230				$ 108,644	$ 120,230
Number of units issued (in shares)							0	0	21,768	0	64,708	25,520	272,400	0	21,768	362,628
Value of units issued							$ 0	$ 0	$ 1,877	$ 0	$ 5,618	$ 2,000	$ 6,810	$ 0	$ 1,877	$ 14,428
Series A Units
Noncontrolling Interest [Line Items]
Fixed priority return on preferred OP units, amount					$ 101,700
Fixed priority return on preferred OP units, stated return rate		2.30%				5.00%
Fixed priority return on preferred OP units, liquidation value						$ 115,000
Preferred units outstanding (in shares)							875,480								875,480
Series A Units | Holders Of Series A Preferred Operating Partnership Units
Noncontrolling Interest [Line Items]
Loan to holders of preferred OP units			$ 100,000				$ 100,000								$ 100,000
Maximum number of preferred OP units converted prior to the maturity date of the loan (in shares)					114,500
Note receivable interest rate		2.10%	4.90%
Additional units redeemed			0
Series B Units
Noncontrolling Interest [Line Items]
Preferred units outstanding (in shares)							1,676,087								1,676,087
Liquidation value (in dollars per share)							$ 25								$ 25
Fixed liquidation value							$ 41,902								$ 41,902
Annual rate of return percent															6.00%
Series C Units
Noncontrolling Interest [Line Items]
Loan to holders of preferred OP units							$ 19,735				$ 20,230				$ 19,735	20,230
Preferred units outstanding (in shares)							296,020								296,020
Note receivable interest rate				5.00%
Liquidation value (in dollars per share)							$ 42.1								$ 42.1
Fixed liquidation value							$ 12,462								$ 12,462
Quarterly distribution per preferred OP unit payable above quarterly distribution for common OP Unit (in dollars per share)															$ 0.18
Basis for determining fixed quarterly distribution in year 5, period before fifth anniversary															12 months
Period from date of issuance after which preferred OP units will become redeemable at the option of the holder															1 year
Period from date of issuance after which preferred OP units will become convertible into common OP units at the option of the holder															1 year
Preferred OP units conversion ratio (in units)															0.9145
Conversion of units, units converted (in shares)	407,996
Series D Units
Noncontrolling Interest [Line Items]
Preferred units outstanding (in shares)							3,682,521								3,682,521
Liquidation value (in dollars per share)							$ 25								$ 25
Fixed liquidation value							$ 92,064								$ 92,064
Value of units issued																$ 11,161	$ 67,193
Series D Units | Minimum
Noncontrolling Interest [Line Items]
Annual rate of return percent															3.00%
Series D Units | Maximum
Noncontrolling Interest [Line Items]
Annual rate of return percent															5.00%
Series D Units | Operating Partnership
Noncontrolling Interest [Line Items]
Number of units issued (in shares)																446,420	2,687,711
Preferred Operating Partnership, Series C
Noncontrolling Interest [Line Items]
Reduction of noncontrolling interest for note receivable							8,644								$ 8,644
Operating Partnership
Noncontrolling Interest [Line Items]
Conversion of units, units issued upon conversion (in shares)	373,113
Reduction of noncontrolling interest for note receivable							$ 11,091								$ 11,091