Benefit Plans - Defined Benefit Plans - Weighted-average Assumptions Used to Determine Net Periodic Cost (Details)	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014
Supplemental Retirement Plan
Weighted-average Assumption Used to Determine Net Periodic Benefit Cost:
Discount rate	3.65%	4.50%
Split-Dollar Life Insurance Benefit Plan
Weighted-average Assumption Used to Determine Net Periodic Benefit Cost:
Discount rate	3.65%	4.50%

The interest rate used to adjust for the time value of money.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(1)
-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920

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