Statement of Equity Statement - USD ($) $ in Millions	Total	Common Stock [Member]	Other Additional Capital [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]	Subsidiaries [Member]	Subsidiaries [Member] Common Stock [Member]	Subsidiaries [Member] Other Additional Capital [Member]	Subsidiaries [Member] AOCI Attributable to Parent [Member]	Subsidiaries [Member] Retained Earnings [Member]	Subsidiaries [Member] Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Shares, Issued		1						41,172,173
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ (471.7)	$ 0.0	$ 2,370.5	$ 2.2	$ (2,844.4)		$ 445.3	$ 0.4	$ 711.8	$ (35.3)	$ (231.6)
Other Comprehensive Income (Loss), Net of Tax	(0.4)						0.4
Net income/ (loss)	42.1						29.0
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	41.7						29.4
Non-cash capital contribution	1.5		1.5
Stockholders' Equity, Other	$ 0.1		(0.1)				$ (0.3)				0.3
Common stock, par value (in USD per share)							$ 0.01
Common Stock, Shares Authorized	1,500						50,000,000
Shares, Issued		1						41,172,173
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ (428.4)	$ 0.0	2,372.1	1.8	(2,802.3)		$ 474.4	$ 0.4	711.8	(34.9)	(202.9)
Common stock, par value (in USD per share)							$ 0.01
Common Stock, Shares Authorized	1,500						50,000,000
Shares, Issued		1						41,172,173
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ (371.9)	$ 0.0	2,370.7	(3.6)	(2,739.0)		$ 473.4
Common Stock, Value, Issued	0.0						0.4
Additional Paid in Capital, Common Stock	2,370.7						617.0
Accumulated Other Comprehensive Income (Loss), Net of Tax	(3.6)					$ 14.5	(36.9)					$ (0.4)
Retained Earnings (Accumulated Deficit)	(2,739.0)						(107.1)
Other Comprehensive Income (Loss), Net of Tax	(0.3)					(0.6)	0.4					(0.4)
Net income/ (loss)	1.9						11.7
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	1.6						$ 12.1
Non-cash capital contribution	$ 0.0
Common stock, par value (in USD per share)							$ 0.01
Common Stock, Shares Authorized	1,500						50,000,000
Shares, Issued		1						41,172,173
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ (370.3)	$ 0.0	$ 2,370.7	$ (3.9)	$ (2,737.1)		$ 485.5	$ 0.4	$ 617.0	$ (36.5)	$ (95.4)
Common Stock, Value, Issued	0.0						0.4
Additional Paid in Capital, Common Stock	2,370.7						617.0
Accumulated Other Comprehensive Income (Loss), Net of Tax	(3.9)					$ 13.9	(36.5)					$ (0.8)
Retained Earnings (Accumulated Deficit)	$ (2,737.1)						$ (95.4)