CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities:
Net income (loss)		$ 24,195	$ (2,444)
Non-cash items included in net income (loss):
Depreciation and amortization		21,381	24,542
Impairment loss			32,311
Stock-based compensation charges		4,637	1,484
Loss from investments in Unconsolidated Affiliates		3,927	4,478
Other non-cash items		2,990	2,466
Changes in operating assets and liabilities that provided (used) cash:
Accounts receivable		161,321	(61,248)
Contracts in progress, net of Advance billings on contracts		(241,700)	50,839
Accounts payable		95,276	16,762
Accrued and other current liabilities		1,869	(16,112)
Other assets and liabilities, net		(25,444)	6,202
Total cash provided by operating activities		48,452	59,280
Cash flows from investing activities:
Purchases of property, plant and equipment	[1]	(62,849)	(31,900)
Proceeds from asset dispositions		55,391
Investments in Unconsolidated Affiliates			(4,105)
Total cash used in investing activities		(7,458)	(36,005)
Cash flows from financing activities:
Repayment of debt		(5,167)	(4,752)
Repurchase of common stock		(6,614)	(2,200)
Total cash used in financing activities		(11,781)	(6,952)
Effects of exchange rate changes on cash, cash equivalents and restricted cash		213	(139)
Net increase in cash, cash equivalents and restricted cash		29,426	16,184
Cash, cash equivalents and restricted cash at beginning of period		612,333	781,645
Cash, cash equivalents and restricted cash at end of period		$ 641,759	$ 797,829

[1] Total capital expenditures represent expenditures for which cash payments were made during the period. Capital expenditures for the first quarter of 2017 and 2016 exclude $2 million in accrued liabilities related to capital expenditures outstanding as of beginning of each respective period.