Balance Sheet Offsetting (Repos - by maturity date and collateral type) (Details 1) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	$ 604,299	$ 504,296
Debt Securities Issued by the U.S. Treasury and Government Agencies
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	314,890	315,463
Debt Securities Issued by States and Political Subdivisions
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	2,790	3,496
Mortgage-Backed Securities: Residential - Government Agencies
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	87,730	97,699
Mortgage-Backed Securities: Residential - U.S. Government-Sponsored Enterprises
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	198,889	87,638
Maturity Up To 90 Days [Member]
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	1,999	2,706
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	490	1,906
Maturity Up To 90 Days [Member] | Mortgage-Backed Securities: Residential - Government Agencies
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	1,509	800
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	2,300	1,590
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	2,300	1,590
Maturity 91 To 365 Days [Member] | Mortgage-Backed Securities: Residential - Government Agencies
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	0	0
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	198,303	198,442
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	26,697	26,558
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	375,000	275,000
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	116,587	117,021
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	0	0
Maturity After 3 Years [Member] | Mortgage-Backed Securities: Residential - Government Agencies
Securities Sold Under Agreements to Repurchase
Securities Sold under Agreements to Repurchase	59,524	70,341
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	$ 198,889	$ 87,638