Variable Interest Entities - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Variable Interest Entities [Abstract]
Expenses associated with LIHTC investments accounted for using the equity method	$ 1.3	$ 4.1	$ 1.8
Variable interest entity, decline in related debt	$ 2.7