Goodwill and Identifiable Intangible Assets - Schedule of Identifiable Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 101,663	$ 99,532
Accumulated Amortization	74,117	66,298
Net Carrying Amount	$ 27,546	33,234
Remaining Weighted-Average Amortization Periods in Years	7 years 4 months 24 days
Core Deposit Intangibles [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 85,824	85,824
Accumulated Amortization	61,603	54,464
Net Carrying Amount	$ 24,221	31,360
Remaining Weighted-Average Amortization Periods in Years	6 years 7 months 6 days
Insurance Intangibles [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 13,824	11,693
Accumulated Amortization	11,117	10,566
Net Carrying Amount	$ 2,707	1,127
Remaining Weighted-Average Amortization Periods in Years	15 years
Banking Charters [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,325	1,325
Accumulated Amortization	811	745
Net Carrying Amount	$ 514	580
Remaining Weighted-Average Amortization Periods in Years	7 years 8 months 12 days
Borrower Relationship Intangible [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 690	690
Accumulated Amortization	586	523
Net Carrying Amount	$ 104	$ 167
Remaining Weighted-Average Amortization Periods in Years	1 year 8 months 12 days