Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash Flows from Continuing Operating Activities:
Net Income (Loss)	$ 33,137	$ (83,346)	$ (100,070)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	57,395	57,167	57,166
Deferred financing cost amortization	1,097	1,107	1,055
Stock-based compensation expense	5,165	4,646	5,363
Debt discount amortization	6,866	6,672	5,662
Allowance for credit losses	863	230	(404)
(Gains) Losses from equipment sales, retirements or impairments	(20,436)	17,588	6,461
Gain from return of investments in 50% or less owned companies	(9,442)
Gain on debt extinguishment	(62,749)
Derivative gains	(391)	(4,310)	(71)
Interest on finance lease	4	1
Cash settlement payments on derivative transactions, net	(2,150)	(1,331)	(482)
Currency losses	1,235	1,294	2,541
Deferred	4,860	2,258	(12,890)
Equity (earnings) losses	(15,078)	8,163	14,459
Dividends received from equity investees	5,332	2,117	2,073
Changes in Operating Assets and Liabilities:
Accounts receivables	22,437	(30,165)	10,182
Other assets	3,113	6,530	554
Accounts payable and accrued liabilities	471	(18,343)	957
Net cash provided by (used in) operating activities	8,973	(29,722)	1,662
Cash Flows from Continuing Investing Activities:
Purchases of property and equipment	(7,003)	(20,808)	(44,775)
Proceeds from disposition of property and equipment	30,137	20,674	55,321
Cash impact of sale of ERRV fleet			(5,140)
Purchase of subsidiary from joint venture		(8,445)
Proceeds from sale of Windcat Workboats, net of transaction costs and cash sold	38,715
Investments in and advances to 50% or less owned companies	(3,008)	(2,206)	(17,395)
Return of investments and advances from 50% or less owned companies			461
Excess distributions from equity investees	9,442
Construction reserve funds transferred to short-term cash		3,745
Construction reserve funds utilized		9,148	15,168
Principal payments on notes due from equity investees	3,345	1,715
Cash received from acquisition of 50% or less owned company	172
Net cash provided by investing activities	71,800	3,823	31,030
Cash Flows from Continuing Financing Activities:
Payments on long-term debt	(78,124)	(22,601)	(23,974)
Payments on debt extinguishment costs	(755)
Proceeds from exercise of stock options and warrants	1	2	1,424
Payments on finance lease	(30)
Issuance of stock	10
Purchase of subsidiary shares from noncontrolling interests			(3,392)
Net cash used in financing activities	(78,898)	(22,599)	(25,942)
Effects of Exchange Rate Changes on Cash, Cash Equivalents and Restricted Cash	(22)	30	(16,619)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash, Continuing Operations	1,853	(48,468)	(9,869)
Cash Flows from Discontinued Operations:
Operating Activities	(171)	8,217	13,778
Investing Activities	0	(8,318)	(15,388)
Financing Activities	0	941	0
Effects of Exchange Rate Changes on Cash, Restricted Cash and Cash Equivalents	0	119	1,674
Net (Decrease) Increase in Cash, Restricted Cash and Cash Equivalents on Discontinued Operations	(171)	959	64
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	1,682	(47,509)	(9,805)
Cash, Cash Equivalents and Restricted Cash, Beginning of Year	39,538	87,047	96,852
Cash, Cash Equivalents and Restricted Cash, End of Year	41,220	39,538	87,047
Supplemental disclosures:
Cash paid for interest, excluding capitalized interest	24,143	21,977	21,479
Income taxes refunded, net	32,759	1,094	1,999
Noncash Investing and Financing Activities:
Increase in property, plant and equipment related to an acquisition		142,282
Decrease in joint venture investments related to an acquisition		22,222
Distribution from equity investee	2,538
Acquisition of 50% or less owned company	23,037
Increase in long-term debt related to an acquisition		75,569
Increase in long-term debt related to asset purchases	6,500	21,252	10,626
Decrease in debt related to debt settlement	62,749
Increase in capital expenditures in accounts payable and accrued liabilities	10,379	$ 3,193	2,409
Recognition of a new right-of-use asset - operating leases	3,582
Windcat Workboats
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Gain (loss) on sale of assets	$ (22,756)
Boston Putford Offshore Safety
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Gain (loss) on sale of assets			9,106
ERRV Fleet Business
Cash Flows from Continuing Investing Activities:
Proceeds from disposition of property and equipment			$ 27,390