Discontinued Operations (Details) - USD ($)		1 Months Ended	3 Months Ended
	Feb. 28, 2020	Jan. 31, 2020	Mar. 31, 2020	Mar. 31, 2019	Mar. 13, 2020	Mar. 02, 2020	Jan. 30, 2020	Oct. 30, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on sale of subsidiary			$ (39,300,000)	$ 0
, Disposal Of subsidiary			(22,800,000)	0
Interest Expense			21,300,000	18,800,000
Amortization of (discount) premium on investments			2,000,000.0	1,600,000
Proceeds from divestiture of businesses			$ 144,000,000.0	$ 0
New Saxon 2019 Limited
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Parents interest, controlling			30.00%				73.00%
Marine Services
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on sale of subsidiary	$ (39,300,000)
, Disposal Of subsidiary	31,300,000
Ownership percentage before sale of stock		100.00%
Consideration to be received							$ 250,000,000.0	$ 140,000,000
Potential earn-out, maximum							12,500,000
Consideration held in escrow for future losses payable							1,250,000
Consideration held of escrow for purchase price adjustment							1,910,000
Consideration to be paid on the earlier of December 31, 2020 or the date on which a cash collateralized bond in connection with Company's bonding facility is released							$ 2,400,000
Proceeds from Divestiture of Businesses, Net of Cash Divested	98,600,000
Proceeds from divestiture of businesses	144,000,000.0
Marine Services | Non- controlling Interest
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash Divested from Deconsolidation	36,800,000
Marine Services | Noncontrolling Interest Redeemable [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash Divested from Deconsolidation	5,500,000
Secured Indenture
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Debt instrument, amount redeemed						$ 76,900,000
Interest Expense			$ 2,200,000
Amortization of debt issuance costs			200,000
Amortization of (discount) premium on investments			100,000
Revolving Credit Agreement
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Face amount	$ 15,000,000.0		15,000,000.0		$ 15,000,000.0
Interest Expense			200,000
Amortization of debt issuance costs			$ 100,000