Fair Value Measurements - Assets and Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	$ 1,245,300	$ 1,098,336
Equity securities	4,706	2,855
U.S. government and agency obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	30,668	42,386
Mortgage-backed securities and collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	1,134,106	979,881
Municipal obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	1,885	2,284
Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	74,181	69,180
Trust preferred securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	4,460	4,605
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	30,668	42,386
Equity securities	4,379	2,587
Derivative assets		0
Derivative liabilities	0	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	1,214,632	1,055,950
Equity securities	327	268
Derivative assets		185
Derivative liabilities	47,873	11,546
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	0	0
Equity securities	0	0
Derivative assets		0
Derivative liabilities	0	0
Measured on recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	1,245,300	1,098,336
Equity securities	4,706	2,855
Derivative assets	22,305	185
Assets	1,272,311	1,101,376
Derivative liabilities	47,873	11,546
Measured on recurring basis | U.S. government and agency obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	30,668	42,386
Measured on recurring basis | Mortgage-backed securities and collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	1,134,106	979,881
Measured on recurring basis | Municipal obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	1,885	2,284
Measured on recurring basis | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	74,181	69,180
Measured on recurring basis | Trust preferred securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	4,460	4,605
Measured on recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	30,668	42,386
Equity securities	4,379	2,587
Derivative assets	0	0
Assets	35,047	44,973
Derivative liabilities	0	0
Measured on recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. government and agency obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	30,668	42,386
Measured on recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Mortgage-backed securities and collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	0	0
Measured on recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Municipal obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	0	0
Measured on recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	0	0
Measured on recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Trust preferred securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	0	0
Measured on recurring basis | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	1,214,632	1,055,950
Equity securities	327	268
Derivative assets	22,305	185
Assets	1,237,264	1,056,403
Derivative liabilities	47,873	11,546
Measured on recurring basis | Significant Other Observable Inputs (Level 2) | U.S. government and agency obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	0	0
Measured on recurring basis | Significant Other Observable Inputs (Level 2) | Mortgage-backed securities and collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	1,134,106	979,881
Measured on recurring basis | Significant Other Observable Inputs (Level 2) | Municipal obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	1,885	2,284
Measured on recurring basis | Significant Other Observable Inputs (Level 2) | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	74,181	69,180
Measured on recurring basis | Significant Other Observable Inputs (Level 2) | Trust preferred securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	4,460	4,605
Measured on recurring basis | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	0	0
Equity securities	0
Derivative assets	0	0
Assets	0	0
Derivative liabilities	0	0
Measured on recurring basis | Significant Unobservable Inputs (Level 3) | U.S. government and agency obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	0	0
Measured on recurring basis | Significant Unobservable Inputs (Level 3) | Mortgage-backed securities and collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	0	0
Measured on recurring basis | Significant Unobservable Inputs (Level 3) | Municipal obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	0	0
Measured on recurring basis | Significant Unobservable Inputs (Level 3) | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	0	0
Measured on recurring basis | Significant Unobservable Inputs (Level 3) | Trust preferred securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available for sale	$ 0	$ 0