Description of Business, Basis of Presentation and Significant Accounting Policies and Recently Issued Accounting Pronouncements - Recently Issued Accounting Pronouncements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Jan. 01, 2019	Jan. 01, 2018	Jan. 01, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of new accounting principle			$ 0	$ 0
ASU 2016-01
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of new accounting principle			$ 93
ASU 2016-02 | Subsequent Event
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease assets		$ 29,300
Operating lease liabilities		$ 30,200
ASU 2018-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of stranded tax effects from accumulated other comprehensive loss to retained earnings	$ 218