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Investment Securities (Available For Sale Securities Unrealized Gains And Losses, By Security Type) (Details) - USD ($) | Jun. 30, 2025 | Dec. 31, 2024
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Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | $ 9,680,135,000 | $ 10,127,426,000
Gross Unrealized Gains | 31,948,000 | 3,961,000
Gross Unrealized Losses | (796,304,000) | (994,534,000)
Allowance for Credit Losses | 0 | 0
Fair Value | 8,915,779,000 | 9,136,853,000
U.S. government and federal agency obligations |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 2,586,856,000 | 2,594,130,000
Gross Unrealized Gains | 23,630,000 | 2,981,000
Gross Unrealized Losses | (12,749,000) | (41,859,000)
Allowance for Credit Losses | 0 | 0
Fair Value | 2,597,737,000 | 2,555,252,000
Government-sponsored enterprise obligations |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 55,032,000 | 55,425,000
Gross Unrealized Gains | 0 | 0
Gross Unrealized Losses | (10,884,000) | (12,576,000)
Allowance for Credit Losses | 0 | 0
Fair Value | 44,148,000 | 42,849,000
State and municipal obligations [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 774,740,000 | 822,790,000
Gross Unrealized Gains | 3,000 | 16,000
Gross Unrealized Losses | (59,785,000) | (79,915,000)
Allowance for Credit Losses | 0 | 0
Fair Value | 714,958,000 | 742,891,000
Agency mortgage-backed securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 3,991,521,000 | 4,195,182,000
Gross Unrealized Gains | 679,000 | 415,000
Gross Unrealized Losses | (636,161,000) | (750,706,000)
Allowance for Credit Losses | 0 | 0
Fair Value | 3,356,039,000 | 3,444,891,000
Non-Agency Mortgage-Backed Securities [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 539,853,000 | 625,539,000
Gross Unrealized Gains | 421,000 | 136,000
Gross Unrealized Losses | (40,278,000) | (56,986,000)
Allowance for Credit Losses | 0 | 0
Fair Value | 499,996,000 | 568,689,000
Asset-backed securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 1,516,911,000 | 1,595,797,000
Gross Unrealized Gains | 6,573,000 | 413,000
Gross Unrealized Losses | (27,161,000) | (39,195,000)
Allowance for Credit Losses | 0 | 0
Fair Value | 1,496,323,000 | 1,557,015,000
Total Mortgage And Asset-Backed Securities [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 6,048,285,000 | 6,416,518,000
Gross Unrealized Gains | 7,673,000 | 964,000
Gross Unrealized Losses | (703,600,000) | (846,887,000)
Allowance for Credit Losses | 0 | 0
Fair Value | 5,352,358,000 | 5,570,595,000
Other debt securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 215,222,000 | 238,563,000
Gross Unrealized Gains | 642,000 | 0
Gross Unrealized Losses | (9,286,000) | (13,297,000)
Allowance for Credit Losses | 0 | 0
Fair Value | $ 206,578,000 | $ 225,266,000

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- Definition This item represents the gross unrealized gains for securities which are categorized as neither held-to-maturity nor trading securities. Such gross unrealized gains are the excess of the fair value of the Available-for-sale Securities over their carrying value as of the reporting date. Such gross unrealized gains are included in other comprehensive income in the statement of shareholders' equity. This concept represents the balance in unrealized gains at period-end. + References No definition available. + Details
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- Definition This item represents the gross unrealized losses for securities which are categorized neither as held-to-maturity nor trading securities. Such gross unrealized losses are the excess of the carrying value of the Available-for-sale Securities over their fair value as of the reporting date. Such gross unrealized losses are included in other comprehensive income in the statement of shareholders' equity. This concept represents the balance in unrealized loss at period end. + References No definition available. + Details
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- Definition Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479130/326-30-45-1 + Details
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