CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
CURRENT ASSETS:
Cash and cash equivalents ($52,871 and $53,067 related to variable interest entities (VIEs))	$ 174,340	$ 192,868
Restricted cash	4,090	4,780
Restricted investments	53,161	53,014
Accounts receivable ($28,076 and $30,003 related to VIEs)	1,236,818	1,265,717
Retainage receivable ($18,627 and $12,410 related to VIEs)	530,897	535,939
Costs and estimated earnings in excess of billings	980,896	932,758
Other current assets ($30,093 and $0 related to VIEs)	132,298	89,316
Total current assets	3,112,500	3,074,392
PROPERTY AND EQUIPMENT, net of accumulated depreciation of $328,443 and $359,188 ($25,072 and $11,641 related to VIEs)	473,178	467,499
GOODWILL	585,006	585,006
INTANGIBLE ASSETS, NET	88,568	89,454
OTHER ASSETS	48,877	47,772
TOTAL ASSETS	4,308,129	4,264,123
CURRENT LIABILITIES:
Current maturities of long-term debt	27,165	30,748
Accounts payable ($9,183 and $19,243 related to VIEs)	659,290	699,971
Retainage payable	246,033	261,820
Billings in excess of cost and estimated earnings ($199,618 and $120,952 related to VIEs)	508,616	456,869
Accrued expenses and other current liabilities	118,334	132,438
Total current liabilities	1,559,438	1,581,846
LONG-TERM DEBT, less current maturities, net of unamortized discounts and debt issuance costs totaling $43,064 and $45,631	790,119	705,528
DEFERRED INCOME TAXES	106,763	108,504
OTHER LONG-TERM LIABILITIES	166,205	163,465
TOTAL LIABILITIES	2,622,525	2,559,343
COMMITMENTS AND CONTINGENCIES (NOTE 9)
Stockholders' Equity:
Preferred stock - authorized 1,000,000 shares ($1 par value), none issued
Common stock - authorized 75,000,000 shares ($1 par value), issued and outstanding 49,913,003 and 49,781,010 shares	49,913	49,781
Additional paid-in capital	1,087,164	1,084,205
Retained earnings	606,199	622,007
Accumulated other comprehensive loss	(43,596)	(42,718)
Total stockholders' equity	1,699,680	1,713,275
Noncontrolling interests	(14,076)	(8,495)
TOTAL EQUITY	1,685,604	1,704,780
TOTAL LIABILITIES AND EQUITY	$ 4,308,129	$ 4,264,123