Acquisitions Acquisitions - Geneva (Details) - USD ($) $ in Thousands		12 Months Ended
	Mar. 01, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition
Goodwill		$ 301,321	$ 238,814	$ 223,105
Geneva Healthcare, Inc.
Business Acquisition
Cash consideration	$ 45,900
Aggregate Estimated Present Value of Additional Consideration	32,000
Total additional consideration to be transferred	20,000
Future value of additional consideration to be paid in cash	11,100
Fair value of additional cash consideration at acquisition date	9,700
Estimated fair value of common stock to be issued as part of additional consideration	9,100
Cash and cash equivalents	1,376
Healthcare accounts receivable	1,500
Prepaid expenses and other current assets	234
Identifiable intangible assets	14,900
Deferred tax assets	1,013
Total assets acquired	19,023
Accounts payable	215
Accrued liabilities	872
Total liabilities assumed	1,087
Total identifiable net assets	17,936
Net assets acquired	77,880
Geneva Healthcare, Inc. | Customer relationships
Business Acquisition
Identifiable intangible assets	$ 3,500
Weighted average life	12 years
Geneva Healthcare, Inc. | Technology
Business Acquisition
Identifiable intangible assets	$ 8,900
Weighted average life	7 years
Geneva Healthcare, Inc. | Trade Names
Business Acquisition
Identifiable intangible assets	$ 2,500
Weighted average life	15 years
Geneva Healthcare, Inc. | Common stock
Business Acquisition
Number of shares issued in a business acquisition	131,594
Healthcare
Business Acquisition
Goodwill		276,014	$ 213,507	$ 198,273
Healthcare | Geneva Healthcare, Inc.
Business Acquisition
Measurement period adjustment - change in consideration		(2,200)
Measurement period adjustment - increase in net deferred tax assets		(2,900)
Goodwill	$ 59,944
Acquisition Related Costs		$ 1,400
Contingent Consideration Liability | Level 3 | Geneva Healthcare, Inc.
Business Acquisition
Fair value of contingent consideration at acquisition date	$ 13,200