Share-Based Payment Arrangements (Narrative) (Details) $ / shares in Units, $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2023 USD ($) shares	Sep. 30, 2023 USD ($) Entity $ / shares shares
Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options expired	1,476
Stock options exercised		0
Restricted and Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation expense | $	$ 51.9	$ 51.9
Weighted-average period		3 years
Total fair value of shares vested | $		$ 9.5
Shares granted		649,023
Grant date fair value per share | $ / shares		$ 48.55
Performance Shares [Member] | Executive Management [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period		3 years
Performance Shares [Member] | Total Shareholder Return [Member] | Executive Management [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted		41,495
Grant date fair value per share | $ / shares		$ 51.14
Vesting performance period		3 years
Number of peer group regional banks | Entity		49
Performance Shares [Member] | Total Shareholder Return [Member] | Executive Management [Member] | Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of maximum number of shares vested		200.00%
Performance Shares [Member] | Operating Earnings Per Share [Member] | Executive Management [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted		41,495
Grant date fair value per share | $ / shares		$ 46.73
Vesting performance period		2 years
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted		500,515