Loan Sales and Servicing - Residential MSRs (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance		$ 51,428
Increase (decrease) in fair value:
Ending balance		50,776
Residential Mortgage
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance		51,428	$ 44,541
Additions		2,018	4,407
Increase (decrease) in fair value:
Due to changes in valuation inputs or assumptions		346	(5,762)
Due to other changes in fair value	[1]	(3,016)	(2,469)
Ending balance		$ 50,776	$ 40,717

[1] Represents the realization of expected net servicing cash flows, expected borrower repayments and the passage of time.