Derivatives and Balance Sheet Offsetting Balance Sheet Offsetting (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Balance Sheet Offsetting [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	$ 9,700,000
Unrealized Gain (Loss) on Interest Rate Cash Flow Hedges, Pretax, Accumulated Other Comprehensive Income (Loss)	23,423,000	$ 6,268,000
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax	940,000	0
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	29,252,000
Repurchase agreements, amounts offset in balance sheet	0		$ 0
Repurchase agreements, net amount presented in statement of financial position	29,252,000		64,437,000
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities	(29,252,000)		(64,437,000)
Securities sold under agreements to repurchase, amount not offset	0		0
Interest Rate Contracts [Member]
Balance Sheet Offsetting [Line Items]
Derivative Assets, Gross Amounts Offset in the Balance Sheets	0		0
Derivative Asset	49,775,000		19,144,000
Derivative, Collateral, Obligation to Return Cash	0		0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	49,775,000		19,144,000
Derivative Liability, Gross Amounts Offset in Balance Sheets	0		0
Derivative Liability	49,777,000		19,145,000
Derivative, Collateral, Right to Reclaim Cash	49,777,000		19,145,000
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	0		0
Interest rate collar [Domain]
Balance Sheet Offsetting [Line Items]
Derivative Assets, Gross Amounts Offset in the Balance Sheets	0		0
Derivative Asset	37,209,000		14,727,000
Derivative, Collateral, Obligation to Return Cash	(37,209,000)		(14,727,000)
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	0		0
Available-for-sale Securities [Member]
Balance Sheet Offsetting [Line Items]
Securities Sold under Agreements to Repurchase, Gross	29,252,000		64,437,000
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Balance Sheet Offsetting [Line Items]
Gain (Loss) on Derivative Instruments, Net, Pretax	0	$ 0
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Other Assets [Member]
Balance Sheet Offsetting [Line Items]
Fair value of asset derivative instruments	49,775,000		19,144,000
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Other Liabilities [Member]
Balance Sheet Offsetting [Line Items]
Fair value of liability derivative instruments	49,777,000		19,145,000
Designated as Hedging Instrument [Member] | Interest rate collar [Domain] | Other Assets [Member]
Balance Sheet Offsetting [Line Items]
Fair value of asset derivative instruments	37,209,000		14,727,000
Designated as Hedging Instrument [Member] | Interest rate collar [Domain] | Other Liabilities [Member]
Balance Sheet Offsetting [Line Items]
Fair value of liability derivative instruments	0		$ 0
U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Balance Sheet Offsetting [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	29,252,000
Maturity Overnight [Member] | U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Balance Sheet Offsetting [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	$ 29,252,000