Fair Value Measurements - Losses Recognized on Assets Measured on a Nonrecurring Basis (Details) - Fair Value, Measurements, Nonrecurring - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total losses	$ 29,204	$ 8,393	$ 41,187	$ 10,145
Non Purchased Credit Impaired Loans and Leases
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total losses	29,047	8,339	40,920	10,091
Other real estate and foreclosed assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total losses	$ 157	$ 54	$ 267	$ 54