CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating Activities
Net loss	$ (23,851)	$ (9,763)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation, depletion and amortization	14,649	13,736
Gain on sales of property and equipment	(270)	(600)
Stock-based compensation	8,913	5,985
Equity in net income from unconsolidated joint ventures	(1,456)	(8,538)
Changes in assets and liabilities:
Receivables	68,272	33,358
Costs and estimated earnings in excess of billings, net	(25,581)	(21,793)
Inventories	(3,536)	(3,891)
Contributions to unconsolidated construction joint ventures	(813)	(2,715)
Distributions from unconsolidated construction joint ventures	16,179	4,512
Other assets, net	(18,465)	(12,448)
Accounts payable	(28,161)	(22,081)
Accrued expenses and other current liabilities, net	7,456	13,804
Net cash provided by (used in) operating activities	13,336	(10,434)
Investing Activities
Purchases of marketable securities	(29,910)	(19,948)
Maturities of marketable securities	30,000	5,000
Proceeds from called marketable securities	0	5,000
Purchases of property and equipment ($6,207 and $8,066 related to CCJVs)	(21,372)	(24,565)
Proceeds from sales of property and equipment	1,060	772
Other investing activities, net	67	(274)
Net cash used in investing activities	(20,155)	(34,015)
Financing Activities
Long-term debt principal repayments	(1,250)	(1,250)
Cash dividends paid	(5,151)	(5,124)
Repurchases of common stock	(6,448)	(4,459)
Other financing activities, net	(157)	744
Net cash used in financing activities	(13,006)	(10,089)
Decrease in cash and cash equivalents	(19,825)	(54,538)
Cash and cash equivalents at beginning of period	189,326	252,836
Cash and cash equivalents at end of period	169,501	198,298
Cash paid during the period for:
Interest	1,242	558
Income taxes	1,897	6,138
Other non-cash operating activities:
Performance guarantees	0	11,870
Non-cash investing and financing activities:
Restricted stock units issued, net of forfeitures	11,109	20,164
Accrued cash dividends	5,176	5,143
Accrued equipment purchases	749	(3,725)
Consolidated Construction Joint Venture | Joint Venture Consolidated
Investing Activities
Purchases of property and equipment ($6,207 and $8,066 related to CCJVs)	6,207	8,066
Financing Activities
Cash and cash equivalents at beginning of period	73,115
Cash and cash equivalents at end of period	$ 60,406	$ 46,993