CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
CURRENT ASSETS:
Cash and cash equivalents	$ 52,116	$ 54,896
Billed accounts receivable, less allowance for credit losses of $7,993 and $9,087, respectively	585,594	619,544
Unbilled accounts receivable, less allowance for credit losses of $815 and $784, respectively	46,834	45,596
Other receivables, less allowance for credit losses of $789 and $759, respectively	38,396	44,212
Inventories	15,653	13,472
Prepaid expenses and other	13,812	15,510
Costs and estimated earnings in excess of billings, less allowance for credit losses of $34 and $79, respectively	10,167	18,622
Total current assets	762,572	811,852
PROPERTY AND EQUIPMENT, NET	115,039	117,206
LEASE RIGHT-OF-USE ASSET	96,782	94,727
GOODWILL	472,778	464,392
IDENTIFIABLE INTANGIBLE ASSETS, NET	230,408	231,807
DEFERRED TAX ASSETS	29,811	29,401
OTHER NONCURRENT ASSETS	8,140	7,970
Total assets	1,715,530	1,757,355
CURRENT LIABILITIES:
Accounts payable	184,499	204,145
Accrued compensation and benefits	104,590	121,864
Billings in excess of costs and estimated earnings	248,397	226,237
Accrued self-insurance	48,106	49,166
Other current liabilities	106,096	91,492
Total current liabilities	691,688	692,904
LONG-TERM DEBT, NET	171,752	235,733
LEASE LIABILITIES	82,661	80,576
DEFERRED TAX LIABILITIES	1,339	1,339
OTHER LONG-TERM LIABILITIES	44,987	50,374
Total liabilities	992,427	1,060,926
COMMITMENTS AND CONTINGENCIES
STOCKHOLDERS' EQUITY:
Preferred stock, $.01 par, 5,000,000 shares authorized, none issued and outstanding
Common stock, $.01 par, 102,969,912 shares authorized, 41,123,365 and 41,123,365 shares issued, respectively	411	411
Treasury stock, at cost, 4,868,862 and 4,935,186 shares, respectively	(128,589)	(129,243)
Additional paid-in capital	326,143	322,451
Retained earnings	525,138	502,810
Total stockholders' equity	723,103	696,429
Total liabilities and stockholders' equity	$ 1,715,530	$ 1,757,355