Employee Benefits - Additional Information (Detail) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
	Jan. 01, 2015	Mar. 31, 2016	Dec. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Pension plan curtailment gain		$ 1.0
Period of unrecognized benefits associated with prior year plan amendments that would have been amortized into income		7 years
Number of consecutive years of employee's compensation			5 years
Number of total years of employee's compensation			10 years
Expected long-term rate of return on plan assets			7.50%
Lump sum death benefit to unmarried beneficiary as percent of accrued benefit payable (percent)	80.00%