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, 2016	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Goodwill balances
Goodwill, net of impairment loss, beginning of period			$ 79,648
Goodwill, Translation and Purchase Accounting Adjustments [Abstract]
Goodwill, net of impairment loss, end of period		$ 117,589	117,589	$ 79,648
Physician Staffing Segment
Goodwill, Translation and Purchase Accounting Adjustments [Abstract]
Impairment charges	$ (17,700)	(5,700)
Operating Segments
Goodwill balances
Goodwill, net of impairment loss, beginning of period			79,648
Sale of CCE			(9,889)	(9,889)
Accumulated impairment loss, beginning of period			(277,452)
Aggregate goodwill acquired, beginning of period			366,989
Goodwill, Translation and Purchase Accounting Adjustments [Abstract]
Goodwill acquired			43,596
Impairment charges			(5,655)
Aggregate goodwill acquired, end of period		410,585	410,585	366,989
Accumulated impairment loss, end of period		283,107	283,107	277,452
Goodwill, net of impairment loss, end of period		117,589	117,589	79,648
Operating Segments | Nurse and Allied Staffing Segment
Goodwill balances
Goodwill, net of impairment loss, beginning of period			44,545
Sale of CCE			0	0
Accumulated impairment loss, beginning of period			(259,732)
Aggregate goodwill acquired, beginning of period			304,277
Goodwill, Translation and Purchase Accounting Adjustments [Abstract]
Goodwill acquired			43,596
Impairment charges			0
Aggregate goodwill acquired, end of period		347,873	347,873	304,277
Accumulated impairment loss, end of period		259,732	259,732	259,732
Goodwill, net of impairment loss, end of period		88,141	88,141	44,545
Operating Segments | Physician Staffing Segment
Goodwill balances
Goodwill, net of impairment loss, beginning of period			25,685
Sale of CCE			0	0
Accumulated impairment loss, beginning of period			(17,720)
Aggregate goodwill acquired, beginning of period			43,405
Goodwill, Translation and Purchase Accounting Adjustments [Abstract]
Goodwill acquired			0
Impairment charges			(5,655)
Aggregate goodwill acquired, end of period		43,405	43,405	43,405
Accumulated impairment loss, end of period		23,375	23,375	17,720
Goodwill, net of impairment loss, end of period		20,030	20,030	25,685
Operating Segments | Other Human Capital Management Services Segment
Goodwill balances
Goodwill, net of impairment loss, beginning of period			9,418
Sale of CCE			(9,889)	(9,889)
Accumulated impairment loss, beginning of period			0
Aggregate goodwill acquired, beginning of period			19,307
Goodwill, Translation and Purchase Accounting Adjustments [Abstract]
Goodwill acquired			0
Impairment charges			0
Aggregate goodwill acquired, end of period		19,307	19,307	19,307
Accumulated impairment loss, end of period		0	0	0
Goodwill, net of impairment loss, end of period		$ 9,418	$ 9,418	$ 9,418