Presentation, Summary of Significant Accounting Policies and Recent Accounting Updates - Impact on Consolidated Statements of Cash Flows Due to Adoption of Amendments in Accounting Updates (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities:
Prepaid expenses, supplies and other current assets	$ (2.4)	$ 0.9	$ 2.1
Debt and equity offering costs	0.0	0.0	(14.5)
Other noncurrent assets	(0.5)	(2.0)	0.2
Net cash used in operating activities of discontinued operations	0.1	(13.9)	1.8
Net cash provided by (used in) operating activities	9.3	93.2	(14.0)
Cash flows from investing activities:
Acquisition of business, net of cash		(524.5)
Proceeds from sale of NABCO	0.0	77.9	0.0
Net cash used in investing activities of discontinued operations	0.0	0.0	(0.1)
Net cash provided by (used in) investing activities	(54.5)	(473.3)	2.9
Cash flows from financing activities:
Other, net	1.2	0.0	(0.1)
Net cash provided by financing activities	35.0	358.0	26.0
Effect of exchange rate changes on cash, cash equivalents, restricted cash and restricted cash equivalents	(0.4)	(0.3)	0.0
Increase (decrease) in cash, cash equivalents, restricted cash and restricted cash equivalents	(10.6)	(22.4)	14.9
Cash, cash equivalents, restricted cash and restricted cash equivalents, beginning of period	43.3	65.7	50.8
Cash, cash equivalents, restricted cash and restricted cash equivalents, end of period	32.7	43.3	65.7
As Previously Reported
Cash flows from operating activities:
Prepaid expenses, supplies and other current assets		3.7
Other noncurrent assets		(5.4)
Net cash used in operating activities of discontinued operations		(14.0)
Net cash provided by (used in) operating activities		92.5	(14.0)
Cash flows from investing activities:
Acquisition of business, net of cash		(524.7)
Proceeds from sale of NABCO		74.1
Net cash provided by (used in) investing activities		(477.3)	2.9
Cash flows from financing activities:
Net cash provided by financing activities		358.0	26.0
Effect of exchange rate changes on cash, cash equivalents, restricted cash and restricted cash equivalents		(0.3)
Increase (decrease) in cash, cash equivalents, restricted cash and restricted cash equivalents		(27.1)	14.9
Cash, cash equivalents, restricted cash and restricted cash equivalents, beginning of period	35.8	62.9	48.0
Cash, cash equivalents, restricted cash and restricted cash equivalents, end of period		35.8	62.9
Impact of Adoption
Cash flows from operating activities:
Prepaid expenses, supplies and other current assets		(2.8)
Other noncurrent assets		3.4
Net cash used in operating activities of discontinued operations		0.1
Net cash provided by (used in) operating activities		0.7	0.0
Cash flows from investing activities:
Acquisition of business, net of cash		0.2
Proceeds from sale of NABCO		3.8
Net cash provided by (used in) investing activities		4.0	0.0
Cash flows from financing activities:
Net cash provided by financing activities		0.0	0.0
Effect of exchange rate changes on cash, cash equivalents, restricted cash and restricted cash equivalents		0.0
Increase (decrease) in cash, cash equivalents, restricted cash and restricted cash equivalents		4.7	0.0
Cash, cash equivalents, restricted cash and restricted cash equivalents, beginning of period	$ 7.5	2.8	2.8
Cash, cash equivalents, restricted cash and restricted cash equivalents, end of period		$ 7.5	$ 2.8