Basis of Presentation - Narrative (Details) - USD ($)		3 Months Ended	9 Months Ended
	Jan. 01, 2020	Sep. 30, 2020	Sep. 30, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase to amortized cost basis of PCD loans to reflect increase in adjustment to allowance for credit losses		$ 5,763,000	$ 6,279,000
Held-to-maturity securities, allowance for credit loss		0	0
Unrealized losses		3,655,000	3,655,000	$ 4,547,000
Cumulative Effect Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase to amortized cost basis of PCD loans to reflect increase in adjustment to allowance for credit losses	$ 700,000
Noncredit discount on PCD loans to be accredited into interest income over remaining life of loans	900,000
Collateralized loan obligations
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Unrealized losses	$ 1,200,000	$ 2,613,000	$ 2,613,000	$ 1,153,000