Pension and Other Postretirement Benefits - Narrative (Details) $ in Thousands	3 Months Ended
Jun. 30, 2019 USD ($)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Contributions by employer	$ 1,463
Additional contributions to the plans	5,171
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Contributions by employer	102
Additional contributions to the plans	$ 386

Amount of contribution received by defined benefit plan from employer which increases plan assets.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration