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Change in Plan Assets and Obligations (Detail) - USD ($) $ in Thousands | 4 Months Ended | 5 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
Jul. 31, 2017 | Dec. 31, 2017 | Dec. 31, 2017 | Mar. 31, 2017
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 |  | $ 103,443 | $ 103,443 |
Fair value of plan assets at end of the period |  | 57,536 | 57,536 |
Predecessor |  |  |  |
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 |  |  |  | $ 97,941
Fair value of plan assets at end of the period |  |  |  | 57,146
Pension Plans, Defined Benefit |  |  |  |
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items] |  |  |  |
Current liabilities |  | (10,731) | (10,731) |
Noncurrent liabilities |  | (35,252) | (35,252) |
Net amount recognized |  | (45,983) | (45,983) |
Pension Plans, Defined Benefit | Predecessor |  |  |  |
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items] |  |  |  |
Actuarial (gain) loss | $ 748 |  |  | 1,785
Current liabilities | (1,791) |  |  | (1,791)
Noncurrent liabilities | (41,642) |  |  | (39,087)
Net amount recognized | (43,433) |  |  | (40,878)
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 |  | 101,490 |  |
Service cost |  | 546 |  |
Interest cost |  | 1,599 |  |
Plan curtailment |  | (432) |  |
Benefits paid |  | (2,059) |  |
Actuarial (gain) loss |  | 2,322 |  |
Foreign currency exchange rate changes |  | (23) |  |
Benefit obligation at end of the period |  | 103,443 | 103,443 |
Pension Plans, Defined Benefit | Change in Benefit Obligations | Predecessor |  |  |  |
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 |  | 97,941 | 95,830
Service cost | 393 |  |  | 1,182
Interest cost | 1,313 |  |  | 3,814
Benefits paid | (1,610) |  |  | (4,895)
Actuarial (gain) loss | 3,322 |  |  | 2,082
Foreign currency exchange rate changes | 131 |  |  | (72)
Benefit obligation at end of the period | 101,490 |  |  | 97,941
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] |  |  |  |
Actuarial (gain) loss |  | (217) |  |
Fair value of plan assets at beginning of the period |  | 58,148 |  |
Actual return |  | 1,182 |  |
Expected return |  | 32 |  |
Administrative expenses |  | (15) |  |
Plan curtailment |  | (100) |  |
Employer contributions |  | 625 |  |
Benefits paid |  | (2,059) |  |
Foreign currency exchange rate changes |  | (60) |  |
Fair value of plan assets at end of the period |  | 57,536 | 57,536 |
Payroll tax unrecognized in benefit obligation at end of the period |  | 76 | 76 |
Unfunded status at end of the period |  | (45,983) |  |
Pension Plans, Defined Benefit | Change In Plan Assets | Predecessor |  |  |  |
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items] |  |  |  |
Actuarial (gain) loss | (109) |  |  | (148)
Fair value of plan assets at beginning of the period | 57,146 |  | 57,146 | 57,174
Actual return | 2,138 |  |  | 577
Expected return | 16 |  |  | 51
Administrative expenses | (7) |  |  | (27)
Employer contributions | 435 |  |  | 4,465
Benefits paid | (1,610) |  |  | (4,895)
Foreign currency exchange rate changes | 139 |  |  | (51)
Fair value of plan assets at end of the period | 58,148 |  |  | 57,146
Payroll tax unrecognized in benefit obligation at end of the period | 91 |  |  | 83
Unfunded status at end of the period | (43,433) |  |  | (40,878)
Other Pension Plans, Defined Benefit |  |  |  |
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items] |  |  |  |
Current liabilities |  | (282) | (282) |
Noncurrent liabilities |  | (2,642) | (2,642) |
Net amount recognized |  | (2,924) | (2,924) |
Other Pension Plans, Defined Benefit | Predecessor |  |  |  |
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items] |  |  |  |
Actuarial (gain) loss | (335) |  |  | (1,138)
Current liabilities | (418) |  |  | (418)
Noncurrent liabilities | (4,399) |  |  | (4,393)
Net amount recognized | (4,817) |  |  | (4,811)
Other 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 |  | 4,817 |  |
Service cost |  | 29 |  |
Interest cost |  | 75 |  |
Participant contributions |  | 65 |  |
Plan amendment |  | (1,861) |  |
Benefits paid |  | (526) |  |
Actuarial (gain) loss |  | 325 |  |
Benefit obligation at end of the period |  | 2,924 | 2,924 |
Other Pension Plans, Defined Benefit | Change in Benefit Obligations | Predecessor |  |  |  |
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 |  | $ 4,811 | 5,573
Service cost | 23 |  |  | 81
Interest cost | 64 |  |  | 201
Participant contributions | 58 |  |  | 411
Benefits paid | (346) |  |  | (1,170)
Actuarial (gain) loss | 207 |  |  | (285)
Benefit obligation at end of the period | 4,817 |  |  | 4,811
Other 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] |  |  |  |
Employer contributions |  | 461 |  |
Participant contributions |  | 65 |  |
Benefits paid |  | (526) |  |
Unfunded status at end of the period |  | $ (2,924) |  |
Other Pension Plans, Defined Benefit | Change In Plan Assets | Predecessor |  |  |  |
Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items] |  |  |  |
Employer contributions | 288 |  |  | 759
Participant contributions | 58 |  |  | 411
Benefits paid | (346) |  |  | (1,170)
Unfunded status at end of the period | $ (4,817) |  |  | $ (4,811)

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