Borrowings - Line of Credit and other disclosures (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Long-term borrowings
Unused line of credit	$ 292,720
FHLB
Long-term borrowings
Unused line of credit	107,850
FRB
Long-term borrowings
Unused line of credit	19,900
Federal Funds Agreements
Long-term borrowings
Unused line of credit	70,000
Repurchase Lines of Credit
Long-term borrowings
Unused line of credit	50,000
Non Recourse Revolving Bank Line of Credit [Member]
Long-term borrowings
Unused line of credit	$ 44,970