Pension Plans - Qualified and Non-Qualified Plans - Expected Amortization Next Fiscal Year (Details) $ in Millions	Dec. 31, 2018 USD ($)
Pension Plan [Member]
Defined Benefit Plan, Expected Amortization, Next Fiscal Year [Abstract]
Defined benefit plan amounts that will be amortized from accumulated other comprehensive loss in the next fiscal year	$ 1.1

Amount of cost (credit) included in accumulated other comprehensive (income) loss expected to be recognized in net periodic benefit cost (credit) for fiscal year following most recent annual statement of financial position.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (s)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

Name:	us-gaap_DefinedBenefitPlanExpectedAmortizationNextFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant