Schedule of Amounts Recognized in Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
UNITED STATES
Defined Benefit Plan Disclosure
Deferred taxes related to prior service cost recognized in other comprehensive income	$ 560	$ 560
Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Prior service cost, before tax	(58)	(249)
Deferred taxes	(1,684)	(1,641)
Deferred taxes related to prior service cost recognized in other comprehensive income	$ (1,742)	$ (1,890)

Amount, after tax and reclassification adjustment, of (increase) decrease in accumulated other comprehensive income for defined benefit plan, attributable to parent.

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