Organization and Summary of Significant Accounting Policies - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accumulated other comprehensive income (loss), interest rate swaps, net of tax	$ 3,500	$ 2,900
Accumulated other comprehensive income (loss), interest rate swap, tax benefit	(2,200)	(1,900)
Accumulated other comprehensive income (loss) related to foreign currency translation, net of tax	(1,900)	(4,800)
Accumulated other comprehensive income (loss), foreign currency translation, tax benefit	$ 0	$ 318