Goodwill and Other Intangible Assets - Narrative (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Goodwill [Line Items]
Expected deductible goodwill for tax purpose	$ 608,000,000
Consumer Bank [Member]
Goodwill [Line Items]
Estimated fair value of the Community Bank unit greater than certain percent of carrying value	76.00%
Accumulated impairment loss	$ 0	$ 0	$ 0
Commercial Bank [Member]
Goodwill [Line Items]
Estimated fair value of the Community Bank unit greater than certain percent of carrying value	29.00%
Accumulated impairment loss	$ 0	$ 0	$ 0
Institutional Bank [Member]
Goodwill [Line Items]
Estimated fair value of the Community Bank unit greater than certain percent of carrying value	34.00%