Other Assets (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other Assets [Line Items]
Proportional amortization as a component of income tax expense	$ 7,000	$ 3,600	$ 2,800
Affordable housing tax credits and other tax benefits, amount	8,400	4,300	$ 3,300
Capital commitments relating to investments	67,000	60,400
Residential Real Estate
Other Assets [Line Items]
Mortgage loans in process of foreclosure	$ 135	$ 7,300