Retirement Plans - Schedule of Impact of Changes in Discount Rate, Return on Plan Assets on Pension Expense (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($)
Compensation and Retirement Disclosure [Abstract]
0.5% decrease in the discount rate, Estimated Effect on Pension Expense	$ (33)
0.5% decrease in the expected long-term rate of return on plan assets, Estimated Effect on Pension Expense	$ 687