Accumulated Other Comprehensive Income (Loss) - Additional Information (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Successor [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Pension and other postretirement benefit plans, tax benefit		$ 0.0	$ 16.9	$ 3.5
Cumulative pension and other postretirement benefit plans, tax benefits		13.4	13.4	3.5
Unrealized gain (loss) on derivatives, tax		2.1	1.7	1.9
Cumulative unrealized gain (loss) on derivatives, tax		(1.9)	0.2	1.9
Predecessor [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Pension and other postretirement benefit plans, tax benefit	$ 0.4
Cumulative pension and other postretirement benefit plans, tax benefits	76.3
Unrealized gain (loss) on derivatives, tax	0.0
Cumulative unrealized gain (loss) on derivatives, tax	0.0
Unrealized holding gain (loss) on securities, tax	0.0
Cumulative unrealized holding gain (loss) on securities, tax benefits	0.9
Pension Plan [Member] | Successor [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Recognized gain (loss) due to curtailments		$ 0.0	$ 7.3	$ 0.0
Pension Plan [Member] | Predecessor [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Recognized gain (loss) due to curtailments	$ 0.0