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Change in Plan Assets and Obligations (Detail) - USD ($) | 4 Months Ended | 5 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
Jul. 31, 2017 | Dec. 31, 2017 | Dec. 31, 2017 | Dec. 31, 2019 | Dec. 31, 2018
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items] |  |  |  |  |  |
Benefit obligation at end of the period |  |  |  |  | $ 91,654,000 | $ 90,247,000
Fair value of plan assets at end of the period |  |  |  |  | 59,625,000 | 56,790,000
Pension Plans, Defined Benefit |  |  |  |  |  |
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items] |  |  |  |  |  |
Actuarial (gain) loss |  | $ 748,000 |  |  |  |
Employer contributions |  |  |  | $ 0 | 1,100,000 | 0
Fair value of plan assets at end of the period |  |  |  |  | 59,095,000 | 56,209,000
Current liabilities |  | (1,791,000) | $ (10,731,000) | (10,731,000) | (1,422,000) | (1,380,000)
Noncurrent liabilities |  | (41,642,000) | (35,252,000) | (35,252,000) | (30,607,000) | (32,161,000)
Net amount recognized |  | (43,433,000) | (45,983,000) | (45,983,000) | (32,029,000) | (33,541,000)
Pension Plans, Defined Benefit | Change In Plan Assets |  |  |  |  |  |
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items] |  |  |  |  |  |
Increase in benefit obligation and plan assets due to business combination |  |  |  |  |  | 5,463,000
Actuarial (gain) loss |  | (109,000) | (217,000) |  | 983,000 | (275,000)
Settlement |  |  |  |  | (4,638,000) | (8,885,000)
Fair value of plan assets at beginning of the period |  | 57,146,000 | 58,148,000 | 57,146,000 | 56,790,000 | 57,536,000
Actual return |  | 2,138,000 | 1,182,000 |  | 7,498,000 | (2,128,000)
Expected return |  | 16,000 | 32,000 |  |  | 112,000
Administrative expenses |  | (7,000) | (15,000) |  | (68,000) | (36,000)
Plan curtailment |  |  | (100,000) |  |  |
Employer contributions |  | 435,000 | 625,000 |  | 5,027,000 | 10,546,000
Benefits paid |  | (1,610,000) | (2,059,000) |  | (5,967,000) | (5,467,000)
Foreign currency exchange rate changes |  | 139,000 | (60,000) |  |  | (76,000)
Fair value of plan assets at end of the period |  | 58,148,000 | 57,536,000 | 57,536,000 | 59,625,000 | 56,790,000
Payroll tax unrecognized in benefit obligation at end of the period |  | 91,000 | 76,000 | 76,000 |  | 84,000
Unfunded status at end of the period |  | (43,433,000) | (45,983,000) |  | (32,029,000) | (33,541,000)
Pension Plans, Defined Benefit | Change in Benefit Obligations |  |  |  |  |  |
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items] |  |  |  |  |  |
Benefit obligation at beginning of the period |  | 97,941,000 | 101,490,000 | 97,941,000 | 90,247,000 | 103,443,000
Increase in benefit obligation and plan assets due to business combination |  |  |  |  |  | 5,474,000
Service cost |  | 393,000 | 546,000 |  | 427,000 | 294,000
Interest cost |  | 1,313,000 | 1,599,000 |  | 3,751,000 | 3,605,000
Plan curtailment |  |  | (432,000) |  |  |
Benefits paid |  | (1,610,000) | (2,059,000) |  | (5,967,000) | (5,467,000)
Actuarial (gain) loss | [1] | 3,322,000 | 2,322,000 |  | 8,198,000 | (8,105,000)
Settlement |  |  |  |  | (4,978,000) | (8,885,000)
Foreign currency exchange rate changes |  | 131,000 | (23,000) |  | (24,000) | (112,000)
Benefit obligation at end of the period |  | 101,490,000 | 103,443,000 | 103,443,000 | $ 91,654,000 | 90,247,000
Other Pension Plan |  |  |  |  |  |
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items] |  |  |  |  |  |
Actuarial (gain) loss |  | (335,000) |  |  |  | 554,000
Current liabilities |  | (418,000) | (282,000) | (282,000) |  |
Noncurrent liabilities |  | (4,399,000) | (2,642,000) | (2,642,000) |  |
Net amount recognized |  | (4,817,000) | (2,924,000) | (2,924,000) |  |
Other Pension Plan | Change In Plan Assets |  |  |  |  |  |
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items] |  |  |  |  |  |
Employer contributions |  | 288,000 | 461,000 |  |  | 377,000
Participant contributions |  | 58,000 | 65,000 |  |  | 218,000
Benefits paid |  | (346,000) | (526,000) |  |  | (595,000)
Unfunded status at end of the period |  | (4,817,000) | (2,924,000) |  |  |
Other Pension Plan | Change in Benefit Obligations |  |  |  |  |  |
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items] |  |  |  |  |  |
Benefit obligation at beginning of the period |  | 4,811,000 | 4,817,000 | 4,811,000 |  | 2,924,000
Service cost |  | 23,000 | 29,000 |  |  | 61,000
Interest cost |  | 64,000 | 75,000 |  |  | 117,000
Participant contributions |  | 58,000 | 65,000 |  |  | 218,000
Plan amendment |  |  | (1,861,000) |  |  | (2,954,000)
Benefits paid |  | (346,000) | (526,000) |  |  | (595,000)
Actuarial (gain) loss |  | 207,000 | 325,000 |  |  | $ 229,000
Benefit obligation at end of the period |  | $ 4,817,000 | $ 2,924,000 | $ 2,924,000 |  |
[1] | The actuarial loss for the year ended December 31, 2019 and the actuarial gain in the year ended December 31, 2018 was primarily attributable to changes in the discount rate.

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