Pension and Employee Benefit Plans - Disclosure of Fair Value Measurements of Pension Plan Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Pension assets, at fair value	$ 28,545	$ 27,099
Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Pension assets, at fair value	18,987	19,702
Debt Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Pension assets, at fair value	7,574	6,819
Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Pension assets, at fair value	28,545	27,099
Level 1 [Member] | Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Pension assets, at fair value	18,987	19,702
Level 1 [Member] | Debt Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Pension assets, at fair value	7,574	6,819
Cash and cash equivalents [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Pension assets, at fair value	1,984	578
Cash and cash equivalents [Member] | Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Pension assets, at fair value	$ 1,984	$ 578