Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended					6 Months Ended	9 Months Ended
	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jan. 01, 2020	Dec. 31, 2019
Summary Of Significant Accounting Policy [Line Items]
Life insurance proceeds received								$ 1,000
Effect on adoption of ASU	$ 64,353						$ 64,353			$ 68,086
Effect on adoption of ASU	20,409						20,409			19,883
Tax benefit in other comprehensive income (loss)	$ 95		$ 34				$ 415	$ 260
ASU 2016-13 [Member]
Summary Of Significant Accounting Policy [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true						true
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Jan. 01, 2020						Jan. 01, 2020
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]	true						true
ASU 2017-04 [Member]
Summary Of Significant Accounting Policy [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true						true
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Jan. 01, 2020						Jan. 01, 2020
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]	true						true
ASU 2018-13 [Member]
Summary Of Significant Accounting Policy [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true						true
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Jan. 01, 2020						Jan. 01, 2020
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]	true						true
ASU 2018-15 [Member]
Summary Of Significant Accounting Policy [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true						true
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Jan. 01, 2020						Jan. 01, 2020
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]	true						true
Effect on adoption of ASU										68,086
Effect on adoption of ASU										$ 19,883
ASU 2018-15 [Member] | Revision of Prior Period, Accounting Standards Update, Adjustment [Member]
Summary Of Significant Accounting Policy [Line Items]
Effect on adoption of ASU									$ (5,600)
Effect on adoption of ASU									$ 5,600
Adjustments for New Accounting Principle, Early Adoption [Member]
Summary Of Significant Accounting Policy [Line Items]
Tax benefit in other comprehensive income (loss)							$ (100)
ASU 2019-12 [Member]
Summary Of Significant Accounting Policy [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true						true
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Apr. 01, 2020						Apr. 01, 2020
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]	true						true
Excess, Obsolete Inventory Reserve and Cost of Goods [Member]
Summary Of Significant Accounting Policy [Line Items]
Amount of revision				$ 800		$ 200
Errors in Operating Activity [Member]
Summary Of Significant Accounting Policy [Line Items]
Amount of revision					$ 1,000
Overstatement Long-term Investment Balance at Remeasured Cost Basis [Member]
Summary Of Significant Accounting Policy [Line Items]
Amount of revision		$ 2,800
Errors in Net Investment Gain [Member]
Summary Of Significant Accounting Policy [Line Items]
Amount of revision		$ 1,500