Commitments and Contingencies - Commitments and Letters of Credit (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Commitment And Contingencies [Line Items]
Total Commitments	$ 1,990,845	$ 1,542,026
Standby letters of credit
Commitment And Contingencies [Line Items]
Total Commitments	80,040	77,134
Commitments to extend credit
Commitment And Contingencies [Line Items]
Total Commitments	$ 1,910,805	$ 1,464,892