Noninterest Income and Noninterest Expense (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Income And Expenses [Abstract]
Net gain on sales of assets	$ 33,200	$ 593	$ 24,654	$ 7,478