Fair Value Measurements - Fair Value Measurement on Nonrecurring Basis (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Servicing Asset at Fair Value, Amount	$ 361
Nonrecurring | Impaired Loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Basis	4,111	$ 1,504
Fair Value	3,380	1,216
Net Losses (Gains) Recorded in Earnings	78	168
Nonrecurring | Impaired Loans | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	0	0
Nonrecurring | Impaired Loans | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	0	0
Nonrecurring | Impaired Loans | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	3,380	1,216
Nonrecurring | Impaired Loans | Commercial and industrial
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Basis		117
Fair Value		107
Net Losses (Gains) Recorded in Earnings		10
Nonrecurring | Impaired Loans | Commercial and industrial | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value		0
Nonrecurring | Impaired Loans | Commercial and industrial | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value		0
Nonrecurring | Impaired Loans | Commercial and industrial | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value		107
Nonrecurring | Impaired Loans | Commercial business
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Basis		1,495
Fair Value		1,209
Net Losses (Gains) Recorded in Earnings		160
Nonrecurring | Impaired Loans | Commercial business | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value		0
Nonrecurring | Impaired Loans | Commercial business | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value		0
Nonrecurring | Impaired Loans | Commercial business | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value		1,209
Nonrecurring | Impaired Loans | Commercial business | Commercial and industrial
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Basis	4,111
Fair Value	3,380
Net Losses (Gains) Recorded in Earnings	78
Nonrecurring | Impaired Loans | Commercial business | Commercial and industrial | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	0
Nonrecurring | Impaired Loans | Commercial business | Commercial and industrial | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	0
Nonrecurring | Impaired Loans | Commercial business | Commercial and industrial | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	3,380
Nonrecurring | Impaired Loans | Consumer
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Basis		9
Fair Value		7
Net Losses (Gains) Recorded in Earnings		8
Nonrecurring | Impaired Loans | Consumer | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value		0
Nonrecurring | Impaired Loans | Consumer | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value		0
Nonrecurring | Impaired Loans | Consumer | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value		7
Reported Value Measurement
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Interest Rate Derivative Liabilities, at Fair Value	8,318	5,095
Fair Value	$ 3,731,708	3,619,118
Commercial Business | Non-owner occupied commercial real estate | Nonrecurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Basis		1,378
Fair Value		1,102
Net Losses (Gains) Recorded in Earnings		150
Commercial Business | Non-owner occupied commercial real estate | Nonrecurring | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value		0
Commercial Business | Non-owner occupied commercial real estate | Nonrecurring | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value		0
Commercial Business | Non-owner occupied commercial real estate | Nonrecurring | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value		$ 1,102