Discontinued Operations - Income (Loss) From Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating expenses
Restructuring expense	$ 211	$ 0
Discontinued Operations, Held-for-sale
Revenues [Abstract]
Total revenue	107,073	104,138
Operating expenses
Selling, general and administrative	10,702	8,930
Depreciation and amortization	0	24,826
Total operating expenses	36,561	79,723
Operating income	70,512	24,415
Other income:
Interest expense	(4,384)	(6,228)
Income before income taxes	66,128	18,187
Income tax expense	17,656	5,057
Income from discontinued operations, net of tax	48,472	13,130
Discontinued Operations, Held-for-sale | Service revenue and other
Revenues [Abstract]
Total revenue	100,674	91,388
Discontinued Operations, Held-for-sale | Equipment revenue
Revenues [Abstract]
Total revenue	6,399	12,750
Discontinued Operations, Held-for-sale | Cost of services
Operating expenses
Cost of services and cost of goods sold	19,427	33,439
Discontinued Operations, Held-for-sale | Cost of goods sold
Operating expenses
Cost of services and cost of goods sold	$ 6,221	$ 12,528