Fair Value Measurements (Narrative) (Details) - Recurring [Member]	Jun. 30, 2021 shares
Visa Inc [Member]
Fair Value of Financial Instruments, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Number of shares of Visa Class B common stock	192,163
Investment Securities [Member] | Minimum [Member]
Fair Value of Financial Instruments, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Targeted duration	2 years
Investment Securities [Member] | Maximum [Member]
Fair Value of Financial Instruments, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Targeted duration	5 years 6 months