Fair Value Measurements - Changes in Fair Value of Loans Held for Sale (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Fair Value, Option, Quantitative Disclosures [Line Items]
Mortgage Banking Income	$ 1,047	[1]	$ 1,313	[1]	$ (18,205)	[1]	$ 2,314	[1]
Loans held for sale
Fair Value, Option, Quantitative Disclosures [Line Items]
Mortgage Banking Income	2,278	[1]	6,892	[1]	9,212	[1]	(7,873)	[1]
Mortgage servicing rights
Fair Value, Option, Quantitative Disclosures [Line Items]
Mortgage Banking Income	$ (1,231)	[1]	$ (5,579)	[1]	$ (27,417)	[1]	$ 10,187	[1]

[1] Does not include the effect of hedging activities.