Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule Of Pre Tax Income [Line Items]
Pre-tax income from U.S. operations	$ 161.9	$ 126.4	$ 112.5
U.S. federal tax at statutory rate	35.00%	35.00%	35.00%
Additional annual limitations	50% or greater change
Percentage of change in ownership	50.00%
Additional annual limitations period	3 years
Capital loss on the sale	$ 20.6
Capital loss carried back	1.2
Undistributed earnings of foreign subsidiaries	36.9
Undistributed earnings of foreign subsidiaries, deferred tax liability	$ 1.2
New York State [Member] | Earliest Tax Year [Member]
Schedule Of Pre Tax Income [Line Items]
Income tax year under examination	2010
New York State [Member] | Latest Tax Year [Member]
Schedule Of Pre Tax Income [Line Items]
Income tax year under examination	2012
Foreign Country [Member]
Schedule Of Pre Tax Income [Line Items]
Pre-tax income from foreign operations	$ 29.7	$ 21.5	$ 6.0
US Country [Member]
Schedule Of Pre Tax Income [Line Items]
Net operating loss carryforwards	$ 5.4
Net operating loss carryforwards, expiration date	2021