Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 43,067	$ 82,985
Accounts receivable, net of allowances of $8,532 and $3,332 at June 30, 2020 and December 31, 2019, respectively	366,574	352,685
Accounts receivable, subcontractor	58,469	72,714
Prepaid expenses	15,547	11,669
Other current assets	34,982	40,446
Total current assets	518,639	560,499
Restricted cash, cash equivalents and investments	56,362	62,170
Fixed assets, net of accumulated depreciation of $145,850 and $132,900 at June 30, 2020 and December 31, 2019, respectively	113,975	104,832
Operating lease right-of-use assets	85,119	89,866
Other assets	120,910	120,254
Goodwill	870,074	595,551
Intangible assets, net of accumulated amortization of $179,916 and $151,417 at June 30, 2020 and December 31, 2019, respectively	599,737	398,474
Total assets	2,364,816	1,931,646
Current liabilities:
Accounts payable and accrued expenses	144,824	156,140
Accrued compensation and benefits	171,007	170,932
Current portion of notes payable	7,813	0
Current portion of operating lease liabilities	15,480	13,943
Deferred revenue	11,759	11,788
Other current liabilities	33,653	25,302
Total current liabilities	384,536	378,105
Revolving credit facility	100,000	0
Notes payable, less unamortized fees	856,106	617,159
Deferred income taxes, net	87,649	46,618
Operating lease liabilities	85,504	91,209
Other long-term liabilities	73,615	61,813
Total liabilities	1,587,410	1,194,904
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.01 par value; 10,000 shares authorized; none issued and outstanding at June 30, 2020 and December 31, 2019	0	0
Common stock, $0.01 par value; 200,000 shares authorized; 49,542 issued and 46,981 outstanding at June 30, 2020 and 49,283 issued and 46,722 outstanding at December 31, 2019	495	493
Additional paid-in capital	461,824	455,193
Treasury stock, at cost (2,561 shares at June 30, 2020 and December 31, 2019)	(119,143)	(119,143)
Retained earnings	434,183	400,047
Accumulated other comprehensive income	47	152
Total stockholders’ equity	777,406	736,742
Total liabilities and stockholders’ equity	$ 2,364,816	$ 1,931,646