Assumptions Used to Determine Net Periodic Benefit Costs (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Discount rate	0.75%	1.25%
Expected long-term return on plan assets	0.75%	1.25%
Rate of compensation increase	1.50%	1.50%