Summary of Significant Accounting Policies - Concentration of Risk (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Concentration of Credit Risk
Sold Receivables Net	$ 85,450	$ 33,825
Sales
Concentration of Credit Risk
Sold Receivables Net	$ 102,700	$ 59,300

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_ConcentrationRiskLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration