Pensions - Pension Plan Assets at Fair Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fair Value Of Pension Plan Assets [Line Items]
Pension plan assets at fair value	$ 321,495	$ 321,891
Equity securities [Member]
Fair Value Of Pension Plan Assets [Line Items]
Pension plan assets at fair value	12,817	34,865
Debt securities [Member]
Fair Value Of Pension Plan Assets [Line Items]
Pension plan assets at fair value	36,133	37,901
Cash and cash equivalents [Member]
Fair Value Of Pension Plan Assets [Line Items]
Pension plan assets at fair value	9,751	1,866
Net Asset Value [Member]
Fair Value Of Pension Plan Assets [Line Items]
Pension plan assets at fair value	262,794	247,259
Net Asset Value [Member] | Equity securities [Member]
Fair Value Of Pension Plan Assets [Line Items]
Pension plan assets at fair value	41,032	117,309
Net Asset Value [Member] | Debt securities [Member]
Fair Value Of Pension Plan Assets [Line Items]
Pension plan assets at fair value	210,492	104,880
Net Asset Value [Member] | Real Estate [Member]
Fair Value Of Pension Plan Assets [Line Items]
Pension plan assets at fair value	11,270	25,070
Level 1 [Member]
Fair Value Of Pension Plan Assets [Line Items]
Pension plan assets at fair value	10,982	20,084
Level 1 [Member] | Equity securities [Member]
Fair Value Of Pension Plan Assets [Line Items]
Pension plan assets at fair value	1,231	18,218
Level 1 [Member] | Debt securities [Member]
Fair Value Of Pension Plan Assets [Line Items]
Pension plan assets at fair value	0	0
Level 1 [Member] | Cash and cash equivalents [Member]
Fair Value Of Pension Plan Assets [Line Items]
Pension plan assets at fair value	9,751	1,866
Level 2 [Member]
Fair Value Of Pension Plan Assets [Line Items]
Pension plan assets at fair value	47,719	54,548
Level 2 [Member] | Equity securities [Member]
Fair Value Of Pension Plan Assets [Line Items]
Pension plan assets at fair value	11,586	16,647
Level 2 [Member] | Debt securities [Member]
Fair Value Of Pension Plan Assets [Line Items]
Pension plan assets at fair value	36,133	37,901
Level 2 [Member] | Cash and cash equivalents [Member]
Fair Value Of Pension Plan Assets [Line Items]
Pension plan assets at fair value	$ 0	$ 0