Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
OPERATING ACTIVITIES:
Net loss	$ (6,293)	$ (31,260)	$ (8,177)
Loss from discontinued operations, net of income taxes	(17,309)	(15,892)	(8,719)
Income (loss) from continuing operations	11,016	(15,368)	542
Adjustments to reconcile net loss to net cash flows provided by operating activities:
Depreciation and amortization	50,389	55,962	54,826
Equity in loss of joint ventures		1,484	2,365
Loss on extinguishment of 7 3/8% senior subordinated notes		2,330
Cash distributions from joint ventures		340
Deferred income taxes	5,760	(32,836)	(494)
Loss on dispositions of property and equipment	3,731	4,789	3,089
Other non-cash restructuring items	2,337	15,678
Amortization of deferred financing fees	3,504	3,280	2,439
Unrealized foreign currency (gain) loss	(231)	(206)	474
Unrealized net (gain) loss from mark-to-market valuations of derivatives		1,747	(6,135)
Share-based compensation expense	4,643	2,917	2,651
Excess income tax benefit from share-based compensation			133
Changes in assets and liabilities:
Accounts receivable	(8,364)	5,354	15,129
Contract revenues in excess of billings	54,881	10,939	(14,183)
Inventories	(921)	(2,163)	(6,239)
Prepaid expenses and other current assets	11,976	(1,868)	(6,583)
Accounts payable and accrued expenses	(1,480)	(16,179)	(8,813)
Billings in excess of contract revenues	7,524	(567)	(730)
Other noncurrent assets and liabilities	(3,093)	(1,658)	(3,751)
Net cash flows provided by operating activities of continuing operations	141,672	33,976	34,720
Net cash flows (used) provided in operating activities of discontinued operations	(4,019)	(12,457)	3,950
Cash provided by operating activities	137,653	21,518	38,670
INVESTING ACTIVITIES:
Purchases of property and equipment	(49,422)	(65,996)	(82,849)
Proceeds from dispositions of property and equipment	13,880	8,586	10,049
Net cash flows used in investing activities of continuing operations	(35,542)	(57,410)	(72,800)
Net cash flows (used) provided by investing activities of discontinued operations	425	(742)	7,259
Cash used in investing activities	(35,117)	(58,152)	(65,541)
FINANCING ACTIVITIES:
Proceeds from issuance of debt		325,000
Repayments of debt	(298)	(276,148)	(45,662)
7 3/8% senior notes tender premium		(744)
Deferred financing fees		(5,022)	(6,818)
Taxes paid on settlement of vested share awards	(1,205)	(328)	(171)
Exercise of stock options and purchases from employee stock plans	1,094	883	905
Excess income tax benefit from share-based compensation			(133)
Borrowings under revolving loans	29,000	124,925	288,611
Repayments of revolving loans	(112,500)	(134,036)	(204,500)
Net cash flows (used) provided in financing activities of continuing operations	(83,909)	34,530	32,232
Net cash flows used in financing activities of discontinued operations	(1,547)	(361)	(1,422)
Cash (used) provided in financing activities	(85,456)	34,169	30,810
Effect of foreign currency exchange rates on cash and cash equivalents	26	115	79
Net increase (decrease) in cash, cash equivalents and restricted cash	17,106	(2,350)	4,018
Cash, cash equivalents and restricted cash at beginning of period	17,352	19,702	15,684
Cash, cash equivalents and restricted cash at end of period	34,458	17,352	19,702
Cash and cash equivalents	34,458	15,852	11,167
Restricted cash included in other long-term assets		1,500	8,535
Cash, cash equivalents and restricted cash at end of period	34,458	17,352	19,702
Supplemental Cash Flow Information
Cash paid for interest	30,855	34,789	26,563
Cash paid for income taxes	290	365	200
Non-cash Investing and Financing Activities
Property and equipment purchased but not yet paid	7,303	$ 4,255	$ 8,795
Repayments of debt with proceeds from sale-leaseback transactions	$ 13,034