Subordinated Notes (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended		3 Months Ended
	Dec. 31, 2014 trust		Dec. 31, 2017		Dec. 31, 2013
Subordinated Notes
Number of trusts sponsored	1
Percentage of ownership interest	100.00%
Subordinated notes
Amount of subordinated notes	$ 58,764				$ 58,764
June 2007 issuance
Subordinated notes
Amount of subordinated notes	41,238
Interest Rate (as a percent)	7.22%	[1]
Maturity date of subordinated notes	Jun. 15, 2037
August 2007 issuance
Subordinated notes
Amount of subordinated notes	$ 17,526
Interest Rate (as a percent)	7.10%	[2]
Maturity date of subordinated notes	Sep. 15, 2037
London Interbank Offered Rate (LIBOR) | Future interest rate | August 2007 issuance
Subordinated notes
Basis Spread on Variable Rate (as a percent)			1.48%	[2]

[1] Fixed rate through life of debt.

[2] Fixed rate through September 15, 2017 then LIBOR +1.48% through remaining life of debt.