CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current Assets:
Cash and cash equivalents	$ 366,619	$ 394,701
Accounts receivable, net of allowances of $5,426 and $5,447	1,283,739	1,328,081
Costs and estimated earnings in excess of billings on uncompleted contracts	407,080	342,777
Inventories	37,666	38,261
Prepaid expenses and other current assets	90,561	97,907
Total current assets	2,185,665	2,201,727
Property and equipment, net of accumulated depreciation of $569,821 and $555,030	1,071,972	1,045,983
Other assets, net	182,871	171,566
Other intangible assets, net of accumulated amortization of $202,780 and $198,082	178,515	183,836
Goodwill	1,535,795	1,537,645
Total assets	5,154,818	5,140,757
Current Liabilities:
Accounts payable and accrued expenses	666,650	707,294
Billings in excess of costs and estimated earnings on uncompleted contracts	163,236	173,885
Total current liabilities	829,886	881,179
Deferred income taxes	227,692	225,050
Insurance and other non-current liabilities	266,419	262,612
Total liabilities	1,323,997	1,368,841
Commitments and Contingencies
Equity:
Common stock, value	2	2
Additional paid-in capital	3,298,026	3,287,086
Retained earnings	740,237	668,156
Accumulated other comprehensive income	710	14,453
Treasury stock, 11,943,338 and 11,646,464 common shares, at cost	(212,844)	(203,149)
Total stockholders' equity	3,826,131	3,766,548
Noncontrolling interests	4,690	5,368
Total equity	3,830,821	3,771,916
Total liabilities and equity	5,154,818	5,140,757
Exchangeable Shares [Member]
Equity:
Common stock, value
Series F Preferred Stock [Member]
Equity:
Series F Preferred Stock, $.00001 par value, 1 share authorized, issued and outstanding