INCOME TAXES -Federal and State Valuation Allowance and Cancellation of Debt Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended	12 Months Ended		24 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016
Increase (decrease) in valuation allowance	$ (82.0)		$ 480.0	$ 398.0
Valuation allowance (as a percent)				199.00%	(7.00%)
Cancellation of debt income, for tax purposes		$ 1,400.0		$ 1,300.0	$ 1,400.0	$ (2,700.0)
Gross deferred tax assets realizable			375.0	375.0		375.0
Reduction of the federal tax basis of property, plant and equipment			1,200.0	1,200.0		1,200.0
Reduction in basis of state plant, property and equipment			1,900.0	1,900.0		1,900.0
Income tax benefit on permanent reduction of tax liability				$ 577.0
Reduction in effective income tax rate on permanent reduction of tax liability				288.00%
Federal
Tax basis of assets			1,500.0	$ 1,500.0		1,500.0
State and Local Jurisdiction
Tax basis of assets			$ 800.0	$ 800.0		$ 800.0