| **Acquisitions - Pro Forma Financial Information (Details) - Level One - USD ($) $ / shares in Units, $ in Thousands** | 3 Months Ended | 6 Months Ended | 12 Months Ended |
|------------------------------------------------------------------------------------------------------------------------|----------------|----------------|-----------------|
||
| **Business Acquisition [Line Items]**                                                                                  |           |           |            |
| Total revenue (net interest income plus other income)                                                                  | $ 156,938      | $ 306,153      | $ 621,946       |
| Net income                                                                                                             | 38,990         | 84,528         | 237,031         |
| Net income available to common stockholders                                                                            | $ 38,521       | $ 83,590       | $ 235,156       |
| **Earnings per common share:**                                                                                         |           |           |            |
| Basic (in dollars per share)                                                                                           | $ 0.64         | $ 1.42         | $ 3.96          |
| Diluted (in dollars per share)                                                                                         | $ 0.63         | $ 1.41         | $ 3.95          |

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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Business Acquisition, Pro Forma Net Income (Loss) Available To Common Stockholders
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| - Definition
The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.
+ References
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The pro forma diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.
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|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.
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| - Definition
The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.
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