Loans Loans (Schedule of Acquired Loans) (Details) - HIghland County Bankshares Inc and Subsidiary First and Citizens Bank [Member] $ in Thousands	Dec. 31, 2016 USD ($)
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Acquired Loans Total Outstanding Balance	$ 56,790
Acquired Loans Purchased Performing Carrying Value	55,612
Commercial Portfolio Segment [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Acquired Loans Purchased Performing Carrying Value	4,292
Owner Occupied [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Acquired Loans Purchased Performing Carrying Value	497
Non Owner Occupied [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Acquired Loans Purchased Performing Carrying Value	3,874
Land And Land Improvements [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Acquired Loans Purchased Performing Carrying Value	4,570
Non Jumbo [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Acquired Loans Purchased Performing Carrying Value	33,002
Jumbo [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Acquired Loans Purchased Performing Carrying Value	4,917
Consumer Portfolio Segment [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Acquired Loans Purchased Performing Carrying Value	4,460
Purchase Nonimpaired Loans [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Acquired Loans Purchase Performing Outstanding Balance	54,076
Acquired Loans Purchased Performing Carrying Value	53,411
Purchase Nonimpaired Loans [Member] | Commercial Portfolio Segment [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Acquired Loans Purchased Performing Carrying Value	4,292
Purchase Nonimpaired Loans [Member] | Owner Occupied [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Acquired Loans Purchased Performing Carrying Value	497
Purchase Nonimpaired Loans [Member] | Non Owner Occupied [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Acquired Loans Purchased Performing Carrying Value	3,874
Purchase Nonimpaired Loans [Member] | Land And Land Improvements [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Acquired Loans Purchased Performing Carrying Value	4,175
Purchase Nonimpaired Loans [Member] | Non Jumbo [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Acquired Loans Purchased Performing Carrying Value	32,213
Purchase Nonimpaired Loans [Member] | Jumbo [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Acquired Loans Purchased Performing Carrying Value	3,900
Purchase Nonimpaired Loans [Member] | Consumer Portfolio Segment [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Acquired Loans Purchased Performing Carrying Value	4,460
Purchased Impaired Loans [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	2,714
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	2,201
Purchased Impaired Loans [Member] | Commercial Portfolio Segment [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	0
Purchased Impaired Loans [Member] | Owner Occupied [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	0
Purchased Impaired Loans [Member] | Non Owner Occupied [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	0
Purchased Impaired Loans [Member] | Land And Land Improvements [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	395
Purchased Impaired Loans [Member] | Non Jumbo [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	789
Purchased Impaired Loans [Member] | Jumbo [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	1,017
Purchased Impaired Loans [Member] | Consumer Portfolio Segment [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	$ 0