Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax [Line Items]
Federal statutory income tax rate	35.00%
Interest related to unrecognized tax benefits	$ 0.1	$ 0.2	$ 0.3
Accrued interest and penalties related to unrecognized tax benefits	0.6	1.0
Unrecognized tax benefits that would affect the Company's effective tax rate if recognized	1.3	1.2
Cash (received) paid for income taxes	5.4	16.4	$ 20.8
Tax credit recognized	$ 1.0	$ 1.0
Maximum [Member]
Income Tax [Line Items]
Income tax year open for examination	2016
Maximum [Member] | State and Local Jurisdiction [Member]
Income Tax [Line Items]
Income tax year open for examination	2016
Minimum [Member]
Income Tax [Line Items]
Income tax year open for examination	2014
Minimum [Member] | State and Local Jurisdiction [Member]
Income Tax [Line Items]
Income tax year open for examination	2007