Retirement Plans - Schedule of Pension Plan Asset Allocation and Target Allocation by Asset Category (Detail)	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets at Year-end	100.00%	100.00%
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets at Year-end	20.00%	33.10%
Equity Securities [Member] \| Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	0.00%
Equity Securities [Member] \| Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	30.00%
Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets at Year-end	80.00%	20.70%
Debt Securities [Member] \| Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	70.00%
Debt Securities [Member] \| Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	100.00%
Money Market Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets at Year-end	0.00%	46.20%
Money Market Funds [Member] \| Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	0.00%

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- Definition

Percentage of target investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=118257860&loc=d3e4179-114921

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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- Definition

Percentage of actual investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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