Statements of Consolidated Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net (losses)/earnings	$ (28,252,000)	$ (44,948,000)	$ 36,433,000
Less: Net (losses)/earnings from discontinued operations, net of tax	(10,000)	122,000	1,032,000
(Losses)/earnings from continuing operations	(28,242,000)	(45,070,000)	35,401,000
Adjustments to reconcile net (losses)/earnings to net cash provided by operating activities:
Depreciation and amortization	61,278,000	62,852,000	52,396,000
Impairment of goodwill	4,719,000	5,500,000	0
Impairment of property, plant and equipment and other assets	4,931,000	8,216,000	1,007,000
(Gain)/loss on disposal of property, plant and equipment and equity method investments	(750,000)	153,000	(938,000)
Gain on extinguishment of debt	0	0	(1,200,000)
Insurance gain recorded in other operating income	(15,710,000)	0	0
(Earnings)/losses from unconsolidated companies, net of tax	(9,355,000)	10,213,000	(11,013,000)
Amortization of debt issuance costs and discount on secured term loan	3,003,000	3,682,000	3,044,000
Share-based compensation	5,364,000	5,809,000	6,272,000
Change in provisions for uncertain tax positions	46,000	160,000	(3,350,000)
Benefit from deferred income tax	(6,219,000)	(13,641,000)	(305,000)
Other non-cash movements	3,671,000	1,596,000	567,000
Effect of exchange rates on net (losses)/earnings	1,121,000	2,424,000	(12,617,000)
Change in assets and liabilities, net of effects from acquisitions:
Accounts receivable	(5,420,000)	(633,000)	1,961,000
Due from unconsolidated companies	2,292,000	(419,000)	(788,000)
Prepaid expense and other	(1,275,000)	(349,000)	668,000
Inventories	724,000	2,539,000	(504,000)
Accounts payable	6,989,000	(2,488,000)	877,000
Accrued liabilities	21,381,000	12,805,000	245,000
Deferred revenue	8,500,000	(489,000)	(1,434,000)
Other liabilities	707,000	(5,633,000)	(14,121,000)
Other, net	928,000	927,000	148,000
Other cash movements:
Dividends from equity method investees	4,290,000	4,440,000	4,449,000
Proceeds from insurance settlements	16,405,000	1,462,000	0
Proceeds from swap termination	359,000	0	0
Payment of swap termination costs	0	(2,145,000)	0
Net cash provided by operating activities from continuing operations	79,737,000	51,911,000	60,765,000
Net cash (used in)/provided by operating activities from discontinued operations	(10,000)	87,000	38,000
Net cash provided by operating activities	79,727,000	51,998,000	60,803,000
Cash flows from investing activities:
Capital expenditure to acquire property, plant and equipment	(166,080,000)	(67,830,000)	(55,104,000)
Capital expenditure to acquire intangible assets	(3,015,000)	0	0
Acquisitions, net of cash acquired	(45,406,000)	(68,632,000)	0
Proceeds from sale of business	0	2,070,000	0
Proceeds from insurance settlements	7,327,000	13,588,000	0
Proceeds from sale of property, plant and equipment and equity method investments	0	0	2,746,000
Net cash used in investing activities from continuing operations	(207,174,000)	(120,804,000)	(52,358,000)
Net cash provided by investing activities from discontinued operations	0	0	0
Net cash used in investing activities	(207,174,000)	(120,804,000)	(52,358,000)
Cash flows from financing activities:
Repurchase of shares	0	0	(1,992,000)
Exercised stock options and vested share awards	7,000	305,000	17,000
Dividend to non-controlling interest	(16,000)	0	(15,000)
Issuance of long-term debt	105,082,000	104,739,000	26,000,000
Debt issuance costs	(1,175,000)	(9,639,000)	(465,000)
Principal payments under long-term debt	(45,278,000)	(5,654,000)	(13,904,000)
Net cash provided by financing activities from continuing operations	58,620,000	89,751,000	9,641,000
Net cash provided by financing activities from discontinued operations	0	0	0
Net cash provided by financing activities	58,620,000	89,751,000	9,641,000
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(3,364,000)	7,120,000	(992,000)
Net (decrease)/increase in cash, cash equivalents and restricted cash	(72,191,000)	28,065,000	17,094,000
Cash, cash equivalents and restricted cash at beginning of period (includes $Nil, $Nil and $Nil of cash presented within assets held for sale)	184,075,000	156,010,000	138,916,000
Cash, cash equivalents and restricted cash at end of period (includes $Nil, $Nil, $Nil of cash presented within assets held for sale)	$ 111,884,000	$ 184,075,000	$ 156,010,000