Schedule of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income Loss [Line Items]
Balance, beginning of period	$ (1.0)
Currency translation adjustments	(2.3)	$ (6.0)	$ 0.0
Pension benefit adjustments	(5.1)	7.1
Deferred tax (expense) benefit on pension benefit adjustment	1.5	(2.1)
Amortization of net actuarial gains	(0.3)	0.0	0.0
Income tax on amortization of net actuarial gains	0.1	0.0	$ 0.0
Balance, end of period	(7.1)	(1.0)
Currency Translation Adjustments
Accumulated Other Comprehensive Income Loss [Line Items]
Balance, beginning of period	(6.0)
Currency translation adjustments	(2.2)	(6.0)
Balance, end of period	(8.2)	(6.0)
Pension Benefit Adjustments
Accumulated Other Comprehensive Income Loss [Line Items]
Balance, beginning of period	5.0
Currency translation adjustments	(0.1)
Pension benefit adjustments	(5.1)	7.1
Deferred tax (expense) benefit on pension benefit adjustment	1.5	(2.1)
Amortization of net actuarial gains	(0.3)
Income tax on amortization of net actuarial gains	0.1
Balance, end of period	$ 1.1	$ 5.0