Description of Business and Summary of Significant Accounting Policies Capitalized Contract Costs (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Deferred Contract Costs [Roll Forward]
Capitalized Contract Cost, Net, beginning of period	$ 2,238	$ 2,401
Capitalized Contract Cost, Amortization	(274)	(898)
Capitalized Contract Costs, net additions	68	735
Capitalized Contract Cost, Net, end of period	$ 2,032	$ 2,238