CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Operating Activities
Net (loss) income	$ (7,579)	$ 8,763
Adjustments to reconcile net (loss) income to net cash provided by (used in) operating activities:
Depreciation, depletion and amortization	31,148	29,502
Gain on sales of property and equipment	(1,077)	(1,966)
Stock-based compensation	11,224	8,563
Equity in net loss (income) from unconsolidated joint ventures	8,249	(5,688)
Gain on real estate entity	0	(2,452)
Changes in assets and liabilities:
Receivables	(64,864)	(87,286)
Costs and estimated earnings in excess of billings, net	(28,284)	(30,645)
Inventories	(10,250)	(9,158)
Contributions to unconsolidated construction joint ventures	(750)	(8,018)
Distributions from unconsolidated construction joint ventures	32,494	5,445
Other assets, net	(9,212)	(7,544)
Accounts payable	52,417	47,529
Accrued expenses and other current liabilities, net	9,170	(158)
Net cash provided by (used in) operating activities	22,686	(53,113)
Investing Activities
Purchases of marketable securities	(49,816)	(29,894)
Maturities of marketable securities	70,000	20,000
Proceeds from called marketable securities	0	35,000
Purchases of property and equipment ($7,492 and $9,044 related to CCJVs)	(37,518)	(48,837)
Proceeds from sales of property and equipment	2,585	2,510
Other investing activities, net	23	(128)
Net cash used in investing activities	(14,726)	(21,349)
Financing Activities
Long-term debt principal repayments	(2,500)	(2,500)
Cash dividends paid	(10,327)	(10,267)
Repurchases of common stock	(6,568)	(4,845)
Other financing activities, net	177	456
Net cash used in financing activities	(19,218)	(17,156)
Decrease in cash and cash equivalents	(11,258)	(91,618)
Cash and cash equivalents at beginning of period	189,326	252,836
Cash and cash equivalents at end of period	178,068	161,218
Cash paid during the period for:
Interest	5,957	6,911
Income taxes	2,554	6,438
Other non-cash operating activities:
Performance guarantees	5,761	11,247
Non-cash investing and financing activities:
Restricted stock units issued, net of forfeitures	11,254	21,013
Accrued cash dividends	5,179	5,148
Accrued equipment purchases	(1,271)	(5,823)
Consolidated Construction Joint Venture | Joint Venture Consolidated
Changes in assets and liabilities:
Net cash provided by (used in) operating activities	19,200	12,800
Investing Activities
Purchases of property and equipment ($7,492 and $9,044 related to CCJVs)	7,492	9,044
Financing Activities
Cash and cash equivalents at beginning of period	73,115
Cash and cash equivalents at end of period	$ 80,195	$ 50,065