Description of Business and Summary of Significant Accounting Policies Advertising Costs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Advertising Costs [Abstract]
Advertising Expense	$ 1,500	$ 1,500
Capitalized Direct Response Advertising Costs [Line Items]
Capital Direct Response Advertising, Amortization		$ 1,000
Minimum [Member]
Capitalized Direct Response Advertising Costs [Line Items]
Capitalized Direct Response Advertising Costs, Amortization Period		12 months
Maximum [Member]
Capitalized Direct Response Advertising Costs [Line Items]
Capitalized Direct Response Advertising Costs, Amortization Period		24 months
ASC 340-40 [Member]
Capitalized Direct Response Advertising Costs [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Net Income	(217)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ (1,932)