Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Stranded tax effects reclassified from accumulated other comprehensive income to retained earnings	$ 315
Estimate of Fair Value, Fair Value Disclosure [Member] | Less unamortized deferred financing fees [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Notes payable, fair value disclosure	$ 75,700	$ 78,000