Mortgage Servicing Rights - Additional Information (Details) - USD ($) $ in Thousands			12 Months Ended
	Apr. 01, 2017	Mar. 07, 2017	Dec. 31, 2016	Mar. 31, 2017
Servicing Assets At Fair Value [Line Items]
Mortgage servicing rights sold			$ 34,118
Mortgage loans serviced			3,332,903
Mortgage Loans Subserviced			$ 3,332,903	$ 787,905
Serviced mortgage loan intended to be sold		$ 1,086,465
Subsequent Event
Servicing Assets At Fair Value [Line Items]
Gain on sale of serviced mortgage loan transaction	$ 17
Servicing asset transaction costs	$ 248