Other Borrowed Funds (Details)	12 Months Ended
Dec. 31, 2015 USD ($) loan	Dec. 31, 2014 USD ($)
Federal Home Loan Bank advances
Balance at year end	$ 505,750,000	$ 1,073,944,000
Federal Home Loan Bank advances short-term
Federal Home Loan Bank advances
Balance at year end	$ 355,750,000	$ 1,067,700,000
Rate on balance outstanding at year end (as a percent)	0.37%	0.15%
Average daily balance	$ 859,220,000	$ 1,077,973,000
Average rate (as a percent)	0.19%	0.16%
Maximum amount outstanding at any month end	$ 1,239,200,000	$ 1,352,500,000
Federal Home Loan Bank advances long-term
Federal Home Loan Bank advances
Balance at year end	$ 150,000,000	$ 6,244,000
Rate on balance outstanding at year end (as a percent)	0.31%	3.51%
Average daily balance	$ 5,314,000	$ 7,338,000
Average rate (as a percent)	0.31%	3.51%
Maximum amount outstanding at any month end	$ 150,000,000	$ 8,934,000
Federal Home Loan Bank advances long-term \| Federal Home Loan Bank advances maturing January 2017
Federal Home Loan Bank advances
Number of long-term advances \| loan	2
Federal Home Loan Bank advances long-term \| Federal Home Loan Bank Advances Maturing January 13 2017
Federal Home Loan Bank advances
Balance at year end	$ 75,000,000
Federal Home Loan Bank advances long-term \| Federal Home Loan Bank Advances Maturing January 25 2017
Federal Home Loan Bank advances
Balance at year end	$ 75,000,000

Number of Long-term borrowings outstanding as of the balance sheet date.

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- Definition

Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

+ Details

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- References

No definition available.

+ Details

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- Definition

The calculated average balance outstanding for the year for all Federal Home Loan Bank advances as of the Balance Sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.13(3)(a))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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- Definition

The calculated weighted average interest rate for Federal Home Loan Bank advances outstanding as of the Balance Sheet date.

+ References

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- Definition

The calculated weighted average interest rate for Federal Home Loan Bank advances for the period ended as of the Balance Sheet date.

+ References

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- Definition

The maximum balance outstanding at any month end during the period as of the Balance Sheet date.

+ References

+ Details

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