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Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
	Jan. 01, 2020	Mar. 31, 2020	Jun. 30, 2019	Jun. 30, 2019
Summary Of Significant Accounting Policy [Line Items]
Life insurance proceeds received				$ 1.0
ASU 2018-15 [Member] | Reclassification of Property, Plant and Equipment to Other Assets [Member]
Summary Of Significant Accounting Policy [Line Items]
Effect on adoption of ASU	$ 5.6
Errors in Operating Activity [Member]
Summary Of Significant Accounting Policy [Line Items]
Amount of revision			$ 1.0
Overstatement Long-term Investment Balance at Remeasured Cost Basis [Member]
Summary Of Significant Accounting Policy [Line Items]
Amount of revision		$ 2.8
Errors in Net Investment Gain [Member]
Summary Of Significant Accounting Policy [Line Items]
Amount of revision		$ 1.5

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Summary of significant accounting policy.

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Amount of cash inflow for proceeds from settlement of corporate-owned life insurance policy, classified as investing activities. Includes, but is not limited to, bank-owned life insurance policy.

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Amount of each individual error being corrected in the correcting adjustment.

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