Comprehensive Income Parenthetical (Parentheticals) - USD ($) $ in Millions	3 Months Ended								9 Months Ended	12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
(Loss) Income from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	$ (175.2)	$ (97.7)	$ (223.2)	$ (167.7)	$ (502.0)	$ (126.4)	$ (1,006.0)	$ (148.8)	$ (423.6)	$ (663.8)	$ (1,783.2)	$ (695.3)
Net change in unrealized (losses) gains on available-for-sale securities, tax (benefit) provision										0.0	(0.1)	(0.5)
Net unrealized gains (losses) on cash flow hedges, tax benefit										85.9	72.2	(54.6)
Postretirement plans and workers' compensation obligations, tax (benefit) provision										(1.5)	36.2	(10.3)
Net (loss) income	(188.3)	(135.8)	(226.2)	(171.1)	(474.3)	(283.9)	(1,042.3)	(157.7)	(477.2)	(721.4)	(1,958.2)	(723.5)
Net Income (Loss) Attributable to Parent	$ (192.7)	$ (137.6)	$ (227.9)	$ (171.1)	$ (473.5)	$ (286.7)	$ (1,044.1)	$ (161.0)	$ (485.1)	(729.3)	(1,965.3)	$ (733.2)
Predecessor [Member]
(Loss) Income from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest										(663.8)	(1,783.2)
Net (loss) income										(721.4)	(1,958.2)
Net Income (Loss) Attributable to Parent										$ (729.3)	$ (1,965.3)
Income (Loss) from Continuing Operations, Per Basic and Diluted Share										$ (36.72)	$ (98.65)	$ (39.51)