Assumptions Used to Calculate Net Periodic Benefit Cost for Domestic Defined Benefit Pension and Postretirement Benefit Plans (Detail)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined benefit pension plans
Net Period Benefit Cost Assumptions [Line Items]
Discount rate	4.00%	4.50%	5.20%
Weighted average rate of future compensation increases	3.80%	3.80%	3.80%
Long-term rate of return on plan assets	8.00%	8.00%	8.00%
Postretirement benefit plans
Net Period Benefit Cost Assumptions [Line Items]
Discount rate	4.00%	4.50%	5.20%
Annual increase in Medicare Part B premium	6.00%	6.00%	6.00%
Net Periodic Benefit Cost | Pre-65
Net Period Benefit Cost Assumptions [Line Items]
Health care cost trend rate	8.50%	7.50%	8.00%
Ultimate cost trend rate	6.10%	5.00%	5.00%
Year that the rate reaches the ultimate cost trend rate	2030	2017	2017
Net Periodic Benefit Cost | Post-65
Net Period Benefit Cost Assumptions [Line Items]
Health care cost trend rate	7.50%	7.50%	8.00%
Ultimate cost trend rate	5.40%	5.00%	5.00%
Year that the rate reaches the ultimate cost trend rate	2030	2017	2017