Pension and Postretirement Benefits - Net Periodic Benefit Cost Not yet Recognized (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Retirement Benefits [Abstract]
Net actuarial loss	$ (69,915)	$ (68,653)
Deferred tax benefit	14,683	14,417
Amounts included in AOCI	$ (55,232)	$ (54,236)

Accumulated Other Comprehensive (Income) Loss, Defined Benefit Pension And Other Postretirement Plans, Tax

No definition available.

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- Definition

Amount, after tax, of accumulated other comprehensive (income) loss for defined benefit plan, that has not been recognized in net periodic benefit cost (credit).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669686-108580

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-Publisher FASB
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-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (i-k)
-URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580

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- References

No definition available.

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- Definition

Amount, before tax, of accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (j)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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