Balance Sheet Offsetting (Repos - by maturity date and collateral type) (Details 1) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	$ 603,206	$ 604,306
Debt Securities Issued by the U.S. Treasury and Government Agencies
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	237,238	237,238
Debt Securities Issued by States and Political Subdivisions
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	1,690	2,790
Mortgage-Backed Securities: Residential - Government Agencies
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	115,734	115,734
Mortgage-Backed Securities: Residential - U.S. Government-Sponsored Enterprises
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	248,544	248,544
Maturity Up To 90 Days [Member]
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	0	1,200
Maturity Up To 90 Days [Member] | Debt Securities Issued by the U.S. Treasury and Government Agencies
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	0	0
Maturity Up To 90 Days [Member] | Debt Securities Issued by States and Political Subdivisions
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	0	1,200
Maturity Up To 90 Days [Member] | Mortgage-Backed Securities: Residential - Government Agencies
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	0	0
Maturity Up To 90 Days [Member] | Mortgage-Backed Securities: Residential - U.S. Government-Sponsored Enterprises
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	0	0
Maturity 91 To 365 Days [Member]
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	2,716	2,616
Maturity 91 To 365 Days [Member] | Debt Securities Issued by the U.S. Treasury and Government Agencies
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	0	0
Maturity 91 To 365 Days [Member] | Debt Securities Issued by States and Political Subdivisions
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	1,200	1,100
Maturity 91 To 365 Days [Member] | Mortgage-Backed Securities: Residential - Government Agencies
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	1,516	1,516
Maturity 91 To 365 Days [Member] | Mortgage-Backed Securities: Residential - U.S. Government-Sponsored Enterprises
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	0	0
Maturity 1 To 3 Years [Member]
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	225,000	225,000
Maturity 1 To 3 Years [Member] | Debt Securities Issued by the U.S. Treasury and Government Agencies
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	199,173	199,173
Maturity 1 To 3 Years [Member] | Debt Securities Issued by States and Political Subdivisions
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	0	0
Maturity 1 To 3 Years [Member] | Mortgage-Backed Securities: Residential - Government Agencies
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	25,827	25,827
Maturity 1 To 3 Years [Member] | Mortgage-Backed Securities: Residential - U.S. Government-Sponsored Enterprises
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	0	0
Maturity After 3 Years [Member]
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	375,490	375,490
Maturity After 3 Years [Member] | Debt Securities Issued by the U.S. Treasury and Government Agencies
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	38,065	38,065
Maturity After 3 Years [Member] | Debt Securities Issued by States and Political Subdivisions
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	490	490
Maturity After 3 Years [Member] | Mortgage-Backed Securities: Residential - Government Agencies
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	88,391	88,391
Maturity After 3 Years [Member] | Mortgage-Backed Securities: Residential - U.S. Government-Sponsored Enterprises
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	$ 248,544	$ 248,544