Fair Value Measurements - Assets and Liabilities Measured at Fair Value, Recurring (Details)	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Costs to sell	8.50%
Assets:
Securities available for sale, at fair value	$ 1,715,987,000	$ 1,846,265,000
Transfers between levels 1, 2 and 3	0	0
Collateralized Mortgage Obligations
Assets:
Securities available for sale, at fair value	736,655,000	895,122,000
Mortgage-backed Securities, Residential
Assets:
Securities available for sale, at fair value	352,897,000	402,605,000
Mortgage-backed Securities, Commercial
Assets:
Securities available for sale, at fair value	552,124,000	469,126,000
Corporate securities
Assets:
Securities available for sale, at fair value	4,200,000	3,826,000
Municipal securities
Assets:
Securities available for sale, at fair value	70,111,000	75,586,000
Recurring basis
Assets:
Interest rate swaps	10,353,000
Interest rate swaps		7,059,000
Mortgage banking derivatives	95,000	10,000
Liabilities:
Interest rate swaps	10,353,000	7,059,000
Mortgage banking derivatives	16,000	3,000
Recurring basis | Collateralized Mortgage Obligations
Assets:
Securities available for sale, at fair value	736,655,000	895,122,000
Recurring basis | Mortgage-backed Securities, Residential
Assets:
Securities available for sale, at fair value	352,897,000	402,605,000
Recurring basis | Mortgage-backed Securities, Commercial
Assets:
Securities available for sale, at fair value	552,124,000	469,126,000
Recurring basis | Corporate securities
Assets:
Securities available for sale, at fair value	4,200,000	3,826,000
Recurring basis | Municipal securities
Assets:
Securities available for sale, at fair value	70,111,000	75,586,000
Recurring basis | Mutual funds
Assets:
Securities available for sale, at fair value	22,123,000	23,405,000
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Interest rate swaps	0
Interest rate swaps		0
Mortgage banking derivatives	0	0
Liabilities:
Interest rate swaps	0	0
Mortgage banking derivatives	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Collateralized Mortgage Obligations
Assets:
Securities available for sale, at fair value	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Mortgage-backed Securities, Residential
Assets:
Securities available for sale, at fair value	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Mortgage-backed Securities, Commercial
Assets:
Securities available for sale, at fair value	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate securities
Assets:
Securities available for sale, at fair value	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Municipal securities
Assets:
Securities available for sale, at fair value	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Mutual funds
Assets:
Securities available for sale, at fair value	22,123,000	23,405,000
Recurring basis | Significant Other Observable Inputs (Level 2)
Assets:
Interest rate swaps	10,353,000
Interest rate swaps		7,059,000
Mortgage banking derivatives	95,000	10,000
Liabilities:
Interest rate swaps	10,353,000	7,059,000
Mortgage banking derivatives	16,000	3,000
Recurring basis | Significant Other Observable Inputs (Level 2) | Collateralized Mortgage Obligations
Assets:
Securities available for sale, at fair value	736,655,000	895,122,000
Recurring basis | Significant Other Observable Inputs (Level 2) | Mortgage-backed Securities, Residential
Assets:
Securities available for sale, at fair value	352,897,000	402,605,000
Recurring basis | Significant Other Observable Inputs (Level 2) | Mortgage-backed Securities, Commercial
Assets:
Securities available for sale, at fair value	552,124,000	469,126,000
Recurring basis | Significant Other Observable Inputs (Level 2) | Corporate securities
Assets:
Securities available for sale, at fair value	4,200,000	3,826,000
Recurring basis | Significant Other Observable Inputs (Level 2) | Municipal securities
Assets:
Securities available for sale, at fair value	69,035,000	74,527,000
Recurring basis | Significant Other Observable Inputs (Level 2) | Mutual funds
Assets:
Securities available for sale, at fair value	0	0
Recurring basis | Significant Unobservable Inputs (Level 3)
Assets:
Interest rate swaps	0
Interest rate swaps		0
Mortgage banking derivatives	0	0
Liabilities:
Interest rate swaps	0	0
Mortgage banking derivatives	0	0
Recurring basis | Significant Unobservable Inputs (Level 3) | Collateralized Mortgage Obligations
Assets:
Securities available for sale, at fair value	0	0
Recurring basis | Significant Unobservable Inputs (Level 3) | Mortgage-backed Securities, Residential
Assets:
Securities available for sale, at fair value	0	0
Recurring basis | Significant Unobservable Inputs (Level 3) | Mortgage-backed Securities, Commercial
Assets:
Securities available for sale, at fair value	0	0
Recurring basis | Significant Unobservable Inputs (Level 3) | Corporate securities
Assets:
Securities available for sale, at fair value	0	0
Recurring basis | Significant Unobservable Inputs (Level 3) | Municipal securities
Assets:
Securities available for sale, at fair value	1,076,000	1,059,000
Recurring basis | Significant Unobservable Inputs (Level 3) | Mutual funds
Assets:
Securities available for sale, at fair value	$ 0	$ 0
Discount Rate | Accounts Receivable | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	0.20
Discount Rate | Accounts Receivable | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	0.60
Discount Rate | Inventories | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	0.50
Discount Rate | Inventories | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	0.70