Commitments, Off-Balance Sheet Arrangements, Legal Proceedings and Regulatory Matters (Details Textuals) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Commitments, Off-Balance Sheet Arrangements, and Contingent Liabilities (Textuals) [Line Items]
Unfunded Commitments	$ 23,000		$ 23,000		$ 24,000
Expense Related to Qualified Affordable Housing Projects	4,000	$ 4,000	14,000	$ 13,000
Remaining Investment in Qualified Affordable Housing Projects	210,000		210,000		132,000
Variable Interest Entity Reporting Entity Involvement Unfunded Obligation Amount	112,000		112,000		51,000
Loans Repurchased Under Make Whole Requests	2,000		$ 2,000		$ 2,000
Loans Sold To Outside Investors Loss ReimbursementSettlement Paid			negligible		negligible
Loans Sold To Outside Investors Original Amount	12,200,000		$ 12,200,000
Loans Sold To Outside Investors Remaining Outstanding Amount	7,600,000		7,600,000
Residential Mortgage Loans Sold With Recourse Risk	44,000		44,000		$ 47,000
Residential Mortgage Loans Sold With Credit Recourse Risk	48,000		48,000		57,000
UnconsolidatedProjectsLowIncomeHousing [Member]
Commitments, Off-Balance Sheet Arrangements, and Contingent Liabilities (Textuals) [Line Items]
Other Investments	224,000		224,000		136,000
PrincipalInvestmentCommitment [Member]
Commitments, Off-Balance Sheet Arrangements, and Contingent Liabilities (Textuals) [Line Items]
Other Investments	$ 26,000		$ 26,000		$ 25,000