Benefit Plans Amortization (Details) $ in Thousands	12 Months Ended
Dec. 31, 2016 USD ($)
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service cost	$ 3,504
Amortization of loss	79
Total	3,583
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service cost	197
Amortization of loss	316
Total	$ 513

Amount included in accumulated other comprehensive income (AOCI) expected to be recognized as components of net periodic benefit cost for the fiscal year that follows the most recent annual statement of financial position, including gain (loss), prior service cost (credit), and transition asset (obligation).

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration