Business Combinations, Goodwill and Intangible Assets Business Combinations, Goodwill and Intangible Assets - Unaudited Pro Forma Financial Information (Details) - Health Integrated, Inc. - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Revenues	$ 801,101	$ 729,938
Net income	$ 46,998	$ 58,232
Earnings per share:
Basic (in dollars per share)	$ 1.39	$ 1.73
Diluted (in dollars per share)	$ 1.34	$ 1.68