Discontinued Operations - Financial Results (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	May 14, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Cash Used In Operating Activities			$ 0	$ (8,500,000)
Net Cash Provided By Investing Activities (1)			1,100,000	238,300,000
Cash Provided by (Used in) Financing Activities, Discontinued Operations			0	21,800,000
Net Cash Provided by (Used in) Discontinued Operations			1,100,000	251,600,000
Income from Discontinued Operations, Net of Taxes	$ 0	$ (1,300,000)	0	(2,200,000)
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax		3,600,000		3,600,000
Net loss from discontinued operations, net of taxes	0	2,300,000	0	1,400,000
ASC [Member] | Discontinued Operations, Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash consideration					$ 258,300,000
Amount held in escrow					$ 1,100,000
Interest expense		0.7		2,000,000.0
Revenues	0	17,700,000	0	27,200,000
Operating expense	0	15,400,000	0	22,500,000
Selling, general and administrative expense	0	800,000	0	2,800,000
Total Expenses	0	17,900,000	0	27,000,000.0
Other expense	0	(1,500,000)	0	(3,000,000.0)
Loss from Discontinued Operations Before Taxes	0	(1,700,000)	0	(2,800,000)
Income tax benefit	0	400,000	0	600,000
Income from Discontinued Operations, Net of Taxes	0	(1,300,000)	0	(2,200,000)
Disposal Group, Including Discontinued Operation, Depreciation and Amortization		1,700,000		1,700,000
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax		3,600,000		3,600,000
Net loss from discontinued operations, net of taxes	$ 0	$ 2,300,000	$ 0	$ 1,400,000