Mortgage Servicing Rights - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Servicing Asset [Abstract]
Unpaid principal balances of loans serviced for others	$ 1,400,000	$ 1,450,000
Mortgage Servicing Rights
Mortgage servicing rights	11,014	11,401	$ 12,800
Estimated future MSR amortization
2016	1,800
2017	1,600
2018	1,400
2019	1,200
2020	1,100
Estimated fair value
Mortgage Servicing Rights
Mortgage servicing rights	$ 11,000	$ 11,400