Fair Value of Financial Instruments - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Fair Value, Option, Quantitative Disclosures [Line Items]
Federal home loan bank and federal reserve stock required to be owned by company	$ 456,000		$ 503,000
Forward contracts
Fair Value, Option, Quantitative Disclosures [Line Items]
Net gains (losses) realized due to changes in fair value of loans	(1,500)	$ (400)
Noninterest income | Residential mortgage loans held for sale
Fair Value, Option, Quantitative Disclosures [Line Items]
Net gains (losses) realized due to changes in fair value of loans	$ 1,900	$ 548