Balance Sheet Details (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Other current assets:
Restricted cash and cash equivalents	$ 19,854	$ 18,626
Income taxes receivable	1,800	6,591
Other	12,386	15,592
Other current assets	34,040	40,809
Fixed assets:
Furniture and equipment	52,024	47,355
Software	239,660	220,971
Leasehold improvements	9,602	9,600
Fixed assets, gross	301,286	277,926
Accumulated depreciation	(179,799)	(161,752)
Fixed assets, net	121,487	116,174
Other assets:
Life insurance cash surrender value	107,360	98,161
Other	38,103	36,959
Other assets	145,463	135,120
Accounts payable and accrued expenses:
Trade accounts payable	55,608	28,089
Subcontractor payable	136,983	79,364
Accrued expenses	45,113	37,849
Loss contingencies	10,746	7,613
Professional liability reserve	6,498	8,897
Other	5,946	6,069
Accounts payable and accrued expenses	260,894	167,881
Accrued compensation and benefits:
Accrued payroll	100,080	59,721
Accrued bonuses and commissions	49,969	34,514
Accrued travel expense	2,434	1,998
Health insurance reserve	6,011	5,590
Workers compensation reserve	10,774	10,244
Deferred compensation	112,342	97,184
Other	6,585	4,163
Accrued compensation and benefits	288,195	213,414
Other long-term liabilities:
Workers compensation reserve	21,911	20,930
Professional liability reserve	30,343	31,997
Unrecognized tax benefits	5,365	5,447
Other	49,239	49,533
Other long-term liabilities	$ 106,858	$ 107,907