Indebtedness - Summary of Indebtedness (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Mortgage Loans Payable, Net		$ 495,956	$ 561,241
Senior Unsecured Notes, Net		204,998	364,457
Unsecured Term Loans, Net		456,638	455,970
Unsecured Credit Facility		189,500	52,500
2016 Notes
Debt Instrument [Line Items]
Senior Unsecured Notes, Gross		$ 0	159,679
Maturity Date		Jan. 15, 2016
2017 Notes
Debt Instrument [Line Items]
Senior Unsecured Notes, Gross		$ 54,981	54,981
Interest Rate		7.50%
Effective Interest Rate		7.52%
Maturity Date		Dec. 01, 2017
2027 Notes
Debt Instrument [Line Items]
Senior Unsecured Notes, Gross		$ 6,070	6,070
Interest Rate		7.15%
Effective Interest Rate		7.11%
Maturity Date		May 15, 2027
2028 Notes
Debt Instrument [Line Items]
Senior Unsecured Notes, Gross		$ 31,901	31,901
Interest Rate		7.60%
Effective Interest Rate		8.13%
Maturity Date		Jul. 15, 2028
2032 Notes
Debt Instrument [Line Items]
Senior Unsecured Notes, Gross		$ 10,600	10,600
Interest Rate		7.75%
Effective Interest Rate		7.87%
Maturity Date		Apr. 15, 2032
2017 II Notes
Debt Instrument [Line Items]
Senior Unsecured Notes, Gross		$ 101,871	101,871
Interest Rate		5.95%
Effective Interest Rate		6.37%
Maturity Date		May 15, 2017
2014 Unsecured Term Loan (A)
Debt Instrument [Line Items]
Unsecured Term Loans, Gross		$ 200,000	200,000
Interest Rate	[1]	3.99%
Maturity Date		Jan. 29, 2021
2015 Unsecured Term Loan (A)
Debt Instrument [Line Items]
Unsecured Term Loans, Gross		$ 260,000	260,000
Interest Rate	[1]	3.39%
Maturity Date		Sep. 12, 2022
Mortgage Loans Payable
Debt Instrument [Line Items]
Mortgage Loans Payable, Gross		$ 498,435	564,891
Unamortized Deferred Financing Costs		(2,905)	(3,714)
Unamortized Premiums		426	64
Mortgage Loans Payable, Net		$ 495,956	561,241
Interest Rate		7.35%
Maturity Date Range, Start		Jun. 01, 2018
Maturity Date Range, End		Sep. 01, 2022
Senior Unsecured Notes
Debt Instrument [Line Items]
Unamortized Deferred Financing Costs		$ (320)	(499)
Senior Unsecured Notes, Gross		205,423	365,102
Unamortized Discounts		(105)	(146)
Senior Unsecured Notes, Net		204,998	364,457
Unsecured Term Loans
Debt Instrument [Line Items]
Unamortized Deferred Financing Costs		(3,362)	(4,030)
Unsecured Term Loans, Gross		460,000	460,000
Unsecured Term Loans, Net		456,638	455,970
Unsecured Credit Facility
Debt Instrument [Line Items]
Unamortized Deferred Financing Costs		(2,876)	(4,204)
Unsecured Credit Facility	[2]	$ 189,500	$ 52,500
Interest Rate		1.77%
Maturity Date	[2]	Mar. 11, 2019
Minimum | Mortgage Loans Payable
Debt Instrument [Line Items]
Interest Rate		4.03%
Effective Interest Rate		3.82%
Maximum | Mortgage Loans Payable
Debt Instrument [Line Items]
Interest Rate		8.26%
Effective Interest Rate		8.26%

[1] The interest rate at December 31, 2016 reflects the interest rate protection agreements we entered into to effectively convert the variable rate to a fixed rate. See Note 12.

[2] The maturity date may be extended an additional year at our election, subject to certain restrictions. Amounts exclude unamortized deferred financing costs of $2,876 and $4,204 as of December 31, 2016 and 2015, respectively, which are included in prepaid expenses and other assets on the consolidated balance sheets.