Fair Value Measurements - Financial Instruments Carried at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Assets:
Derivative instruments, at fair value	$ 4,181	$ 2,070
Residential mortgage servicing rights, at fair value	84,638	93,065
Liabilities:
Derivative instruments, at fair value	11,906	3,625
Recurring
Assets:
Cash held in money market funds		586
Loans, held for sale, at fair value	206,185	115,258
Loans, net at fair value	20,434	22,664
Mortgage backed securities, at fair value	96,181	91,937
Derivative instruments, at fair value	4,181	2,070
Residential mortgage servicing rights, at fair value	84,638	93,065
Total assets	411,619	325,580
Liabilities:
Derivative instruments, at fair value	11,906	3,625
Contingent consideration		1,207
Total liabilities	11,906	4,832
Recurring | Level 1
Assets:
Cash held in money market funds		586
Total assets		586
Recurring | Level 2 inputs
Assets:
Loans, held for sale, at fair value	206,185	115,258
Mortgage backed securities, at fair value	65,888	79,789
Derivative instruments, at fair value		294
Total assets	272,073	195,341
Liabilities:
Derivative instruments, at fair value	11,906	3,625
Total liabilities	11,906	3,625
Recurring | Level 3 inputs
Assets:
Loans, net at fair value	20,434	22,664
Mortgage backed securities, at fair value	30,293	12,148
Derivative instruments, at fair value	4,181	1,776
Residential mortgage servicing rights, at fair value	84,638	93,065
Total assets	$ 139,546	129,653
Liabilities:
Contingent consideration		1,207
Total liabilities		$ 1,207