Summary of Significant Accounting Policies - Recently Issued Accounting Pronouncements (Details) - USD ($)	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Simplifying the Presentation of Debt Issuance Costs
Assets	$ 166,641,000	$ 136,784,000	$ 125,560,000
Liabilities	88,054,000	96,085,000	89,568,000
Retrospective basis | Accounting Standards Update ("ASU") 2015-03 - Simplifying the Presentation of Debt Issuance Costs
Simplifying the Presentation of Debt Issuance Costs
Assets	(129,000)	(724,000)	(765,000)
Liabilities	$ (129,000)	$ (724,000)	$ (765,000)