Mortgage Servicing Rights - Schedule of Changes in Mortgage Servicing Rights (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Transfers And Servicing [Abstract]
Carrying value prior to policy change	$ 48,464	$ 40,382	$ 32,070	$ 29,711
Fair value impact of change in accounting policy (See Note 1)			1,011
Carrying value at beginning of period	48,464	40,382	33,081	29,711
Capitalization	15,965	11,107	45,624	30,890
Amortization		(2,796)		(6,221)
Sales			(11,935)
Impairment		(2,402)		(8,089)
Change in fair value:
Due to pay-offs/pay-downs	(975)		(1,772)
Due to change in valuation inputs or assumptions	(408)		(1,952)
Carrying value at June 30	$ 63,046	$ 46,291	$ 63,046	$ 46,291

Servicing asset amortized value to fair value adjustment.

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Servicing asset at fair value, changes in fair value due to pay-offs or pay-downs.

+ References

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Amount of other-than-temporary impairment (OTTI) applied to contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

+ References

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Amortized amount of contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

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Amount of additions from purchases, assumption or transfer to contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

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Amount of amortization of contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

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Amount conveyed to unrelated parties of contract to contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

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Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

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Amount of increase (decrease) in fair value from changes in the inputs, assumptions, or model used to calculate the fair value of the contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

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