Description of Business and Significant Accounting Policies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jul. 01, 2018	Jan. 01, 2018	Jan. 01, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment of adopting ASU 2014-09				$ (900)
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning balance	$ 2,492	$ 1,091	$ 1,856
Additions	234	1,720	368
Deductions	(692)	(319)	(1,133)
Ending balance	$ 2,034	$ 2,492	$ 1,091
Accounting Standards Update 2016-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment of adopting ASU 2014-09						$ (97)
Accounting Standards Update 2016-09 [Member] | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment of adopting ASU 2014-09						$ 137
Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment of adopting ASU 2014-09					$ 396
Accounting Standards Update 2014-09 [Member] | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment of adopting ASU 2014-09					$ 396