Fair Value Option Summary of Corporation's Mortgage Loans Held for Sale (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans Held-for-sale, Mortgages	$ 33,980		$ 33,980		$ 17,522
Mortgage Loans Held For Sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Gain (loss) in fair values of mortgage loans held for sale	(483)	$ 518	(222)	$ 815
Mortgage Loans Held For Sale [Member] | Cost [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans Held-for-sale, Mortgages	33,760		33,760		17,080
Mortgage Loans Held For Sale [Member] | Fair Value [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans Held-for-sale, Mortgages	$ 33,980		$ 33,980		$ 17,522