Discontinued Operations - Summary of Net Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Costs and expenses:
Income from discontinued operations	$ 0	$ 5,878
Income tax expense	0	2,021
Net income from discontinued operations	$ 0	3,857
CBR business | Discontinued Operations, Held-for-sale or Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Service revenues, net		28,969
Costs and expenses:
Cost of services		5,474
Selling, general and administrative expenses		17,619
Total costs and expenses		23,093
Operating income		5,876
Other income		2
Income from discontinued operations		5,878
Income tax expense		2,021
Net income from discontinued operations		$ 3,857