CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Operating Activities
Net income	$ 41,546	$ 41,293
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	43,651	45,691
Non-cash restructuring, net	(1,782)	1,031
Other non-cash impairment charges	3,101	0
Gain on sales of property and equipment	(6,493)	(11,572)
Stock-based compensation	8,910	8,994
(Gain) loss on company owned life insurance	(1,829)	639
Changes in assets and liabilities, net of the effects of a deconsolidation:
Receivables	(115,066)	(112,790)
Costs and estimated earnings in excess of billings, net	(11,342)	(66,045)
Inventories	(13,024)	(6,969)
Increase Decrease Real Estate Held For Development And Sale	(98)	2,756
Equity in construction joint ventures	3,139	(22,699)
Other assets, net	20,312	9,359
Accounts payable	51,025	86,900
Accrued expenses and other current liabilities, net	(2,083)	30,942
Net cash provided by operating activities	20,163	2,018
Investing Activities
Purchase of marketable securities	(59,936)	(115,146)
Maturities of marketable securities	70,100	85,875
Proceeds from sale of marketable securities	55,000	33,268
Additions to property and equipment	(25,971)	(34,748)
Proceeds from sales of property and equipment	8,368	20,071
Other investing activities, net	1,165	2,313
Net cash provided by (used in) investing activities	48,726	(8,367)
Financing Activities
Long-term debt principal payments	(11,584)	(17,293)
Cash dividends paid	(15,078)	(15,090)
Purchase of common stock	(4,521)	(3,840)
Distributions to noncontrolling partners, net	(8,022)	(17,489)
Other financing activities	648	1,138
Net cash used in financing activities	(38,557)	(52,574)
Increase (decrease) in cash and cash equivalents	30,332	(58,923)
Cash and cash equivalents at beginning of period	256,990	252,022
Cash and cash equivalents at end of period	287,322	193,099
Cash paid during the period for:
Interest	6,948	9,718
Income taxes	1,131	905
Non-cash investing and financing activities:
Restricted stock/units issued, net of forfeitures	11,532	6,896
Accrued cash dividends	5,032	5,026
Debt payments out of escrow from sale of assets	1,109	3,446
Debt extinguishment from joint venture interest transfer	9,115	0
Debt payment from refinance	$ 1,150	$ 0