Investment Securities - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Marketable Securities [Abstract]
Debt securities, AFS, accrued interest receivable	$ 12,300,000
Carrying amount of equity investments without a readily determinable fair value	25,900,000		$ 25,600,000
Unrealized gain (loss) for equity investments with readily determinable fair values	$ (5,700,000)	$ 3,400,000