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Fair Value Option and Fair Value Measurements (Details 2) (USD $) In Thousands, unless otherwise specified	6 Months Ended									6 Months Ended
	Jun. 30, 2014 Interest rate swap agreements net of swap credit valuation	Jun. 30, 2013 Interest rate swap agreements net of swap credit valuation	Jun. 30, 2013 Collateralized mortgage obligation	Jun. 30, 2014 Asset-backed securities	Jun. 30, 2013 Asset-backed securities	Jun. 30, 2014 States and political subdivisions	Dec. 31, 2013 States and political subdivisions	Jun. 30, 2013 States and political subdivisions	Dec. 31, 2012 States and political subdivisions	Jun. 30, 2014 Mortgage Servicing rights	Jun. 30, 2013 Mortgage Servicing rights
Changes in Level 3
Balance at the beginning of the period	$ 6	$ (47)	$ 9,957	$ 154,137		$ 125	$ 125	$ 132	$ 132	$ 5,807	$ 4,116
Total gains or losses
Included in earnings (or changes in net assets)	(6)	24	115	1,671	276					(630)	239
Included in other comprehensive income			1,182	513	(1,450)
Purchases, issuances, sales, and settlements
Purchases				58,047	164,533
Issuances										324	946
Settlements			(910)
Sales				(77,282)	(11,591)
Balance at the end of the period		$ (23)	$ 10,344	$ 137,086	$ 151,768	$ 125	$ 125	$ 132	$ 132	$ 5,501	$ 5,301

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Amount of gain (loss) recognized in the income statement for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of gain (loss) recognized in other comprehensive income (loss) for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of issuances of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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