Borrowings - Notes payable (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Debt Instrument
Capital lease obligations	$ 0	$ 20,412
Notes payable	1,211,579	1,256,102
Advances with FHLB with maturities ranging from 2019 Through 2029
Debt Instrument
Advances with the FHLB	517,587	524,052
Advances with the FHLB paying interest monthly at a floating rate
Debt Instrument
Advances with the FHLB	0	13,000
Floating rate over the 3 month LIBOR with maturities on 2019
Debt Instrument
Advances with the FHLB	14,430	19,724
Fixed Rate with maturities on 2023 paying interest semiannually \| Unsecured senior debt
Debt Instrument
Long Term Debt	294,673	294,039
Fixed Rate with maturities ranging from 2033 to 2034 \| Junior subordinated debt
Debt Instrument
Long Term Debt	$ 384,889	$ 384,875

Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

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Including both current and noncurrent portions, Federal Home Loan Bank borrowings initially due beyond one year or beyond the normal operating cycle if longer.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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