Asset Allocation for the Pension Plans and the Target Allocation, by Asset Category (Detail) (Pension Plans, Defined Benefit)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan, Actual Plan Asset Allocations	100.00%	100.00%
Equity Securities
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	0.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	60.00%
Defined Benefit Plan, Actual Plan Asset Allocations	48.00%	59.00%
Debt Securities [Member]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	40.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	100.00%
Defined Benefit Plan, Actual Plan Asset Allocations	49.00%	39.00%
Cash Equivalents [Member]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	0.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	10.00%
Defined Benefit Plan, Actual Plan Asset Allocations	3.00%	2.00%