Balance Sheet Details (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other current assets:
Restricted cash and cash equivalents	$ 25,506	$ 20,271
Income taxes receivable	15,898	361
Other	9,589	13,975
Other current assets	50,993	34,607
Fixed assets:
Furniture and equipment	29,494	25,582
Technology and software	132,770	112,405
Leasehold improvements	9,056	6,832
Fixed assets, gross	171,320	144,819
Accumulated depreciation	(97,889)	(84,865)
Fixed assets, net	73,431	59,954
Accounts payable and accrued expenses:
Trade accounts payable	31,420	33,392
Subcontractor payable	41,786	51,973
Accrued expenses	40,403	37,251
Professional liability reserve	7,672	10,254
Other	9,038	4,642
Accounts payable and accrued expenses	130,319	137,512
Accrued compensation and benefits:
Accrued payroll	33,923	30,917
Accrued bonuses and commissions	19,489	26,992
Accrued travel expense	3,256	2,972
Accrued health insurance reserve	3,658	3,189
Accrued workers compensation reserve	8,553	8,406
Deferred compensation	49,330	32,690
Other	3,214	2,827
Accrued compensation and benefits	121,423	107,993
Other current liabilities:
Acquisition related liabilities	2,599	6,921
Other	2,547	9,690
Other current liabilities	5,146	16,611
Other long-term liabilities:
Workers compensation reserve	19,074	18,708
Professional liability reserve	38,964	37,338
Deferred rent	14,744	13,274
Unrecognized tax benefits	5,270	8,464
Other	1,227	4,312
Other long-term liabilities	$ 79,279	$ 82,096