Credit Concentration - Top Five Geographic Concentrations (Details) - Sales Revenue, Services, Net $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)
Concentration Risk [Line Items]
Total ABR	$ 286,014
Percent of ABR	100.00%
Texas | Geographic Concentration Risk
Concentration Risk [Line Items]
Total ABR	$ 44,064
Percent of ABR	15.40%
Georgia | Geographic Concentration Risk
Concentration Risk [Line Items]
Total ABR	$ 24,716
Percent of ABR	8.60%
Nebraska | Geographic Concentration Risk
Concentration Risk [Line Items]
Total ABR	$ 19,824
Percent of ABR	6.90%
Nebraska | Geographic Concentration Risk
Concentration Risk [Line Items]
Total ABR	$ 17,739
Percent of ABR	6.20%
Minnesota | Geographic Concentration Risk
Concentration Risk [Line Items]
Total ABR	$ 17,154
Percent of ABR	6.00%
Other | Geographic Concentration Risk
Concentration Risk [Line Items]
Total ABR	$ 162,517
Percent of ABR	56.90%