Employee Benefits - Asset Target Allocations Prescribed by Pension Funds' Investment Policies (Detail)	12 Months Ended
	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Total Target Allocation	100.00%
Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Target Allocation	40.00%
Convertible Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Target Allocation	5.00%
Real Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Target Allocation	13.00%
Other Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Target Allocation	6.00%
United States Pension Plan of US Entity [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Target Allocation	20.00%
Foreign Pension Plan [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Target Allocation	16.00%