Employee Benefit Plans (Weighted Average Assumptions Used to Determine Net Periodic Benefit Cost for Defined Benefit Pension and Other Postretirement Plans) (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate used to calculate benefit obligation	3.20%	3.70%
Discount rate	3.60%	3.60%	3.80%
Expected return on assets	5.40%	6.10%	6.10%
Rate of compensation increase	1.30%	1.60%	2.00%
UNITED STATES
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate used to calculate benefit obligation	3.70%	4.30%