Discontinued Operations - Disposal Groups, Including Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Discontinued Operations And Disposal Groups [Abstract]
Service revenue	$ 466	$ 1,165
Product sales	2,465	4,233
Total revenue	2,931	5,398
Cost of services, exclusive of depreciation expense shown below	345	690
Cost of product sales, exclusive of depreciation expense shown below	1,554	3,196
Other Expense (income)	117	91
Operating income (loss)	915	1,421
Adjustment to gain on sale	8,804	8,804
Income (loss) from discontinued operations before income tax expense	9,719	10,225
Income tax expense (benefit)	1,748	1,995
Income (loss) from discontinued operations, net of income taxes	$ 7,971	$ 8,230