Goodwill, Trade Names, and Other Intangible Assets - Changes in Carrying Amount of Goodwill by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Jun. 30, 2020	Dec. 31, 2018	Dec. 31, 2020
Goodwill balances
Aggregate goodwill acquired, beginning of period			$ 411,285
Accumulated impairment loss, beginning of period			(300,330)
Goodwill, net of impairment loss, beginning of period			101,066
Impairment charges			(10,142)
Reclassification of API goodwill			0
Reclassification of API goodwill			0
Aggregate goodwill acquired, end of period			411,285
Accumulated impairment loss, end of period			(310,472)
Goodwill, net of impairment loss, end of period			90,924
Sale of business
Goodwill balances
Aggregate goodwill acquired, beginning of period			9,889
Aggregate goodwill acquired, end of period			9,889
Nurse and Allied Staffing
Goodwill balances
Aggregate goodwill acquired, beginning of period			346,130
Accumulated impairment loss, beginning of period			(259,732)
Goodwill, net of impairment loss, beginning of period			86,398
Impairment charges			0
Reclassification of API goodwill			24
Reclassification of API goodwill			24
Aggregate goodwill acquired, end of period			346,130
Accumulated impairment loss, end of period			(259,732)
Goodwill, net of impairment loss, end of period			86,422
Nurse and Allied Staffing | Sale of business
Goodwill balances
Aggregate goodwill acquired, beginning of period			0
Aggregate goodwill acquired, end of period			0
Physician Staffing
Goodwill balances
Aggregate goodwill acquired, beginning of period			43,405
Accumulated impairment loss, beginning of period			(40,598)
Goodwill, net of impairment loss, beginning of period			2,807
Impairment charges		$ (17,200)	0
Reclassification of API goodwill			0
Reclassification of API goodwill			0
Aggregate goodwill acquired, end of period			43,405
Accumulated impairment loss, end of period			(40,598)
Goodwill, net of impairment loss, end of period			2,807
Physician Staffing | Sale of business
Goodwill balances
Aggregate goodwill acquired, beginning of period			0
Aggregate goodwill acquired, end of period			0
Search
Goodwill balances
Aggregate goodwill acquired, beginning of period			21,750
Accumulated impairment loss, beginning of period			0
Goodwill, net of impairment loss, beginning of period			11,861
Impairment charges	$ (10,200)		(10,142)
Reclassification of API goodwill			(24)
Reclassification of API goodwill			(24)
Aggregate goodwill acquired, end of period			21,750
Accumulated impairment loss, end of period			(10,142)
Goodwill, net of impairment loss, end of period			1,695
Search | Sale of business
Goodwill balances
Aggregate goodwill acquired, beginning of period			9,889
Aggregate goodwill acquired, end of period			$ 9,889