Stock-Based Compensation - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2016	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 0.9	$ 0.8
Share-based compensation expense, net of tax	$ 0.6	0.4
Stock Incentive Plan 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options, outstanding (in shares)	2,096,535
Number of shares available for grant (in shares)	490,926
Share based payment awards performance period	4 years
Employee Stock Option | Stock Incentive Plan 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options, outstanding (in shares)	1,474,752				1,547,980
Share-based compensation expense	$ 0.5
Award vesting rights	25.00%
Award vesting period	1 year
Expiration period	7 years
Compensation not yet recognized	$ 5.5
Compensation cost not yet recognized, period for recognition	1 year 10 months 10 days
Restricted Stock Units (RSUs) | Stock Incentive Plan 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 0.1
Award vesting rights	25.00%
Award vesting period	4 years
Number of shares authorized (in shares)						233,400
Percentage of annual return on assets				1.00%
Stock issued during period (in shares)			108,456
Restricted Stock And Restricted Stock Units | Stock Incentive Plan 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 0.2
Compensation not yet recognized, Share-based awards other than options		$ 7.0
Weighted average remaining contractual terms	3 years 2 months
Minimum | Restricted Stock Units (RSUs) | Stock Incentive Plan 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
Executive Officer | Minimum | Restricted Stock Units (RSUs) | Stock Incentive Plan 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years