Fair Value of Financial Instruments - Hierarchy Table on Noncrecurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Level 1
Fair Value Disclosures
Collateral dependent loans/Impaired loans	$ 0	$ 0
Level 2
Fair Value Disclosures
Collateral dependent loans/Impaired loans	0	0
Level 3
Fair Value Disclosures
Collateral dependent loans/Impaired loans	13,578,530	8,691,019
Nonrecurring
Fair Value Disclosures
Collateral dependent loans/Impaired loans	4,749	2,257
Nonrecurring | Level 1
Fair Value Disclosures
Collateral dependent loans/Impaired loans	0	0
Nonrecurring | Level 2
Fair Value Disclosures
Collateral dependent loans/Impaired loans	0	0
Nonrecurring | Level 3
Fair Value Disclosures
Collateral dependent loans/Impaired loans	$ 4,749	$ 2,257