Segment Information (Details) $ in Millions	3 Months Ended	10 Months Ended
Mar. 31, 2018 USD ($) segment	Mar. 31, 2017 USD ($)	Oct. 16, 2017 segment
Segment Reporting [Abstract]
Number of Operating Segments \| segment	3		2
Segment Reporting Information [Line Items]
Revenues	$ 211.2	$ 374.3
Operating expenses:
Direct operating costs (excluding items below)	157.4	171.3
Depreciation and amortization	97.9	99.1
Selling, general and administrative	25.6	24.2
Other operating items	1.3	3.4
Income (Loss) from Equity Method Investments	(1.3)	0.0
INCOME (LOSS) FROM OPERATIONS	(72.3)	76.3
Deepwater Segment [Member]
Segment Reporting Information [Line Items]
Revenues	52.1	160.7
Jack-ups [Member]
Segment Reporting Information [Line Items]
Revenues	150.1	213.6
Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues	269.5	374.3
Operating expenses:
Direct operating costs (excluding items below)	190.8	171.3
Depreciation and amortization	114.5	99.1
Selling, general and administrative	32.0	24.2
Other operating items	1.4	3.4
Income (Loss) from Equity Method Investments	0.0
INCOME (LOSS) FROM OPERATIONS	(69.2)	76.3
Operating Segments [Member] \| Deepwater Segment [Member]
Segment Reporting Information [Line Items]
Revenues	52.1	160.7
Operating expenses:
Direct operating costs (excluding items below)	29.0	44.9
Depreciation and amortization	26.9	28.3
Selling, general and administrative	0.0	0.0
Other operating items	0.0	0.0
Income (Loss) from Equity Method Investments	0.0
INCOME (LOSS) FROM OPERATIONS	(3.8)	87.5
Operating Segments [Member] \| Jack-ups [Member]
Segment Reporting Information [Line Items]
Revenues	150.1	213.6
Operating expenses:
Direct operating costs (excluding items below)	128.4	126.4
Depreciation and amortization	70.3	70.1
Selling, general and administrative	0.0	0.0
Other operating items	1.3	3.4
Income (Loss) from Equity Method Investments	0.0
INCOME (LOSS) FROM OPERATIONS	(49.9)	13.7
Operating Segments [Member] \| ARO Segment [Member]
Segment Reporting Information [Line Items]
Revenues	58.3	0.0
Operating expenses:
Direct operating costs (excluding items below)	33.4	0.0
Depreciation and amortization	16.6	0.0
Selling, general and administrative	6.4	0.0
Other operating items	0.1	0.0
Income (Loss) from Equity Method Investments	0.0
INCOME (LOSS) FROM OPERATIONS	1.8	0.0
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues	(58.3)	0.0
Operating expenses:
Direct operating costs (excluding items below)	(33.4)	0.0
Depreciation and amortization	(16.6)	0.0
Selling, general and administrative	(6.4)	0.0
Other operating items	(0.1)	0.0
Income (Loss) from Equity Method Investments	(1.3)
INCOME (LOSS) FROM OPERATIONS	(3.1)	0.0
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Revenues	9.0	0.0
Operating expenses:
Direct operating costs (excluding items below)	0.0	0.0
Depreciation and amortization	0.7	0.7
Selling, general and administrative	25.6	24.2
Other operating items	0.0	0.0
Income (Loss) from Equity Method Investments	0.0
INCOME (LOSS) FROM OPERATIONS	$ (17.3)	(24.9)
Parent Company [Member] \| Saudi Arabia Joint Venture [Member]
Operating expenses:
Equity Method Investment, Ownership Percentage	50.00%
SAUDI ARABIA \| Jack-ups [Member]
Segment Reporting Information [Line Items]
Revenues	$ 87.9	94.2
SAUDI ARABIA \| Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Revenues	9.0	0.0
UNITED STATES \| Deepwater Segment [Member]
Segment Reporting Information [Line Items]
Revenues	52.1	160.7
UNITED STATES \| Jack-ups [Member]
Segment Reporting Information [Line Items]
Revenues	1.4	10.8
NORWAY \| Jack-ups [Member]
Segment Reporting Information [Line Items]
Revenues	38.8	51.2
TRINIDAD AND TOBAGO \| Jack-ups [Member]
Segment Reporting Information [Line Items]
Revenues	11.6	41.4
UNITED KINGDOM \| Jack-ups [Member]
Segment Reporting Information [Line Items]
Revenues	10.4	15.5
Other Countries [Member] \| Jack-ups [Member]
Segment Reporting Information [Line Items]
Revenues	$ 0.0	$ 0.5
Saudi Aramco [Member] \| Saudi Arabia Joint Venture [Member]
Operating expenses:
Equity Method Investment, Ownership Percentage	50.00%

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