Defined Pension Benefit Obligations - Narrative (Details) $ in Thousands |
1 Months Ended | 3 Months Ended | 6 Months Ended | |||
---|---|---|---|---|---|---|
Dec. 15, 2017 |
Dec. 31, 2017
USD ($)
|
Mar. 30, 2018
USD ($)
Plan
|
Mar. 31, 2017
USD ($)
|
Mar. 30, 2018
USD ($)
Plan
|
Mar. 31, 2017
USD ($)
|
|
Defined Benefit Plan Disclosure [Line Items] | ||||||
Settlement loss | $ 0 | $ (41) | $ (3,819) | $ (84) | ||
CH2M HILL Companies, Ltd. | ||||||
Defined Benefit Plan Disclosure [Line Items] | ||||||
Defined benefit pension plan assets | 1,100,000 | 1,100,000 | ||||
Defined benefit pension plan liabilities | $ 1,200,000 | $ 1,200,000 | ||||
Business acquisition effective date of acquisition | Dec. 15, 2017 | |||||
U.S. | Sverdrup Pension Plan | ||||||
Defined Benefit Plan Disclosure [Line Items] | ||||||
Settlement loss | $ 3,800 | |||||
U.S. | CH2M HILL Companies, Ltd. | ||||||
Defined Benefit Plan Disclosure [Line Items] | ||||||
Number of noncontributory defined benefit pension plans | Plan | 3 | 3 |