Description of Business and Summary of Significant Accounting Policies Capitalized Contract Costs (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 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	(666)	(898)
Capitalized Contract Costs, net additions	330	735
Capitalized Contract Cost, Net, end of period	$ 1,902	$ 2,238

Amount, after accumulated amortization and accumulated impairment loss, of asset recognized from cost incurred to obtain or fulfill contract with customer.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 40
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=68051541&loc=SL49131252-203054

Name:	us-gaap_CapitalizedContractCostNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant