Segment Data - Operating Segments (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	$ 215,606	$ 193,968	$ 216,779	$ 210,064	$ 215,096	$ 209,200	$ 202,757	$ 195,171	$ 836,417	$ 822,224	$ 816,484
Contribution income									77,788	66,288	71,718
Unallocated corporate overhead									51,900	46,246	44,589
Depreciation and amortization									12,671	14,075	11,780
Acquisition and integration-related costs									77	201	3,048
Restructuring costs	$ 900	$ 2,300	$ 2,300	$ 600	$ 700	$ 1,600		$ 1,200	6,052	3,571	2,758
Legal settlement charges							$ 1,600		0	1,600	0
Impairment charges									16,248	16,306	22,423
Loss from operations									(9,160)	(15,711)	(12,880)
Nurse and Allied Staffing
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues									757,949	732,815	718,613
Contribution income									75,293	64,353	66,200
Physician Staffing
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues									67,934	74,605	82,305
Contribution income									3,619	2,758	4,755
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Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues									10,534	14,804	15,566
Contribution income									$ (1,124)	$ (823)	$ 763