Fair Value Measurement (Losses Resulting From Nonrecurring Fair Value Adjustments) (Details) - Fair Value, Measurements, Nonrecurring - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loss from nonrecurring measurements	$ 1,859,732	$ 70,969	$ 61,004
Loans and leases
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loss from nonrecurring measurements	74,297	67,956	59,727
Goodwill (Wholesale Bank and Retail Bank)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loss from nonrecurring measurements	1,784,936	0	0
Other real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loss from nonrecurring measurements	$ 499	$ 3,013	$ 1,277