Summary of Significant Accounting Policies - Debt Issuance Costs (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Debt issuance costs for revolving credit facility	$ 7,476	$ 7,476
Accumulated amortization of debt issuance costs for revolving credit facility	4,375	2,624
Future amortization of deferred financing fees in 2017	4,858
Future amortization of deferred financing fees in 2018	4,205
Future amortization of deferred financing fees in 2019	2,416
Future amortization of deferred financing fees in 2020	2,166
Future amortization of deferred financing fees in 2021	1,612
Future amortization of deferred financing fees, thereafter	3,380
Unsecured term loan
Debt Instrument [Line Items]
Debt issuance costs, net	$ 15,536	12,800
Long-term debt | Accounting Standards Update 2015-03 | Unsecured term loan
Debt Instrument [Line Items]
Debt issuance costs, net		2,244
Long-term debt | Accounting Standards Update 2015-03 | Senior notes
Debt Instrument [Line Items]
Debt issuance costs, net		10,556
Other assets | Accounting Standards Update 2015-03 | Unsecured term loan
Debt Instrument [Line Items]
Debt issuance costs, net		(2,244)
Other assets | Accounting Standards Update 2015-03 | Senior notes
Debt Instrument [Line Items]
Debt issuance costs, net		$ (10,556)