CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net income		$ 34,122	$ 24,195
Non-cash items included in net income:
Depreciation and amortization	[1]	22,776	21,381
Stock-based compensation charges		6,642	4,637
Loss from investments in Unconsolidated Affiliates		3,713	3,927
Other non-cash items		2,642	2,990
Changes in operating assets and liabilities that provided (used) cash:
Accounts receivable		(67,672)	161,321
Contracts in progress, net of Advance billings on contracts		142,890	(241,700)
Accounts payable		(89,641)	95,276
Accrued and other current liabilities		5,752	1,869
Other assets and liabilities, net		(24,128)	(25,444)
Total cash provided by operating activities		37,096	48,452
Cash flows from investing activities:
Purchases of property, plant and equipment	[2]	(18,386)	(62,849)
Proceeds from asset dispositions		52	55,391
Investments in Unconsolidated Affiliates		(1,565)
Total cash used in investing activities		(19,899)	(7,458)
Cash flows from financing activities:
Repayment of debt		(103)	(5,167)
Repurchase of common stock		(6,513)	(6,614)
Other		(79)
Total cash used in financing activities		(6,695)	(11,781)
Effects of exchange rate changes on cash, cash equivalents and restricted cash		105	213
Net increase in cash, cash equivalents and restricted cash		10,607	29,426
Cash, cash equivalents and restricted cash at beginning of period		408,192	612,333
Cash, cash equivalents and restricted cash at end of period		$ 418,799	$ 641,759

[1] Depreciation and amortization expense associated with our marine vessels is included in the respective segments in which the vessels were located as of the reporting date.

[2] Liabilities associated with assets acquired during the first quarter of 2018 and 2017 were $10 million and $9 million, respectively.