Retirement Plan (Details) - NET Services - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Defined contribution plan, employers matching contribution vesting period	5 years
Corporate
Segment Reporting Information [Line Items]
Defined contribution plan, employer discretionary contribution amount	$ 342	$ 340	$ 304