Derivative Instruments and Hedging Activities (Effect of Fair Value Hedges on Consolidated Statements of Income) (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
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Derivative [Line Items]
Gain (Loss) Recognized in Consolidated Statements of Income			$ 2,500
Derivatives not designated as hedging instruments
Derivative [Line Items]
Gain (Loss) Recognized in Consolidated Statements of Income	$ (5,683)	$ 3,724		$ (12)	$ 4,878
Derivatives not designated as hedging instruments | Interest rate contracts | Capital markets income
Derivative [Line Items]
Gain (Loss) Recognized in Consolidated Statements of Income	(637)	653		310	49
Derivatives not designated as hedging instruments | Other contracts | Capital markets income
Derivative [Line Items]
Gain (Loss) Recognized in Consolidated Statements of Income	(19)	4		182	(333)
Derivatives not designated as hedging instruments | Mortgage derivatives | Mortgage derivatives - interest rate lock commitments | Mortgage banking income
Derivative [Line Items]
Gain (Loss) Recognized in Consolidated Statements of Income	(53)	(634)		(1,772)	6,390
Derivatives not designated as hedging instruments | Mortgage derivatives | Mortgage derivatives - forward commitments to sell fixed-rate mortgage loans | Mortgage banking income
Derivative [Line Items]
Gain (Loss) Recognized in Consolidated Statements of Income	$ (4,974)	$ 3,701		$ 1,268	$ (1,228)