Employee Benefit Plans - Assumptions Used in Measuring Net Periodic Benefit (Income) Cost (Detail) - Pension Benefits [Member]	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Weighted average discount rate	4.82%	4.26%	5.10%
Rate of increase in future compensation levels	3.12%	3.07%	3.04%
Expected long-term rate of return on plan assets	7.83%	7.85%	7.85%