Condensed Consolidated Statements of Changes in Shareholder's Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings (Deficit)
Beginning Balance at Dec. 31, 2013	$ 3,753.4	$ 2.8	$ 3,953.3	$ 495.4	$ (698.1)
Comprehensive income:
Net income (loss)	231.7				231.7
Other comprehensive income (loss), after tax	346.1			346.1
Comprehensive income (loss)	577.8
Dividends paid and distribution of capital	(371.0)		(371.0)
Employee related benefits	1.6		1.6
Ending Balance at Dec. 31, 2014	3,961.8	2.8	3,583.9	841.5	(466.4)
Comprehensive income:
Net income (loss)	173.2				173.2
Other comprehensive income (loss), after tax	(454.7)			(454.7)
Comprehensive income (loss)	(281.5)
Dividends paid and distribution of capital	(321.0)		(321.0)
Employee related benefits	9.7		9.7
Ending Balance at Dec. 31, 2015	3,369.0	2.8	3,272.6	386.8	(293.2)
Comprehensive income:
Net income (loss)	112.8				112.8
Other comprehensive income (loss), after tax	172.7			172.7
Comprehensive income (loss)	285.5
Dividends paid and distribution of capital	(278.0)		(278.0)
Employee related benefits	(0.2)		(0.2)
Ending Balance at Dec. 31, 2016	$ 3,376.3	$ 2.8	$ 2,994.4	$ 559.5	$ (180.4)