Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 116,556	$ 189,961
Accounts receivable:
Billed receivables	455,707	390,996
Unbilled receivables	368,360	312,569
Allowance for doubtful accounts and unbilled services	(216,612)	(180,687)
Accounts receivable, net	607,455	522,878
Current portion of notes receivable	28,619	25,691
Prepaid expenses and other current assets	54,806	55,649
Total current assets	807,436	794,179
Property and equipment, net	75,046	75,075
Goodwill	1,198,732	1,204,803
Other intangible assets, net	39,379	44,150
Notes receivable, net	90,904	98,105
Other assets	45,915	40,929
Total assets	2,257,412	2,257,241
Current liabilities
Accounts payable, accrued expenses and other	93,988	94,873
Accrued compensation	224,663	268,513
Billings in excess of services provided	33,653	46,942
Total current liabilities	352,304	410,328
Long-term debt, net	371,662	396,284
Deferred income taxes	134,081	124,471
Other liabilities	123,564	134,187
Total liabilities	981,611	1,065,270
Commitments and contingent liabilities (Note 11)
Stockholders' equity
Preferred stock, $0.01 par value; shares authorized — 5,000; none outstanding	0	0
Common stock, $0.01 par value; shares authorized — 75,000; shares issued and outstanding — 38,179 (2018) and 37,729 (2017)	382	377
Additional paid-in capital	280,201	266,035
Retained earnings	1,128,670	1,045,774
Accumulated other comprehensive loss	(133,452)	(120,215)
Total stockholders' equity	1,275,801	1,191,971
Total liabilities and stockholders' equity	$ 2,257,412	$ 2,257,241