Consolidated Statements of Stockholders' Equity - USD ($)	Total	Share Repurchase Program	Dividend Reinvestment Plan	Voting Common Stock	Voting Common Stock Share Repurchase Program	Class B Non-Voting	Non-Voting Common Stock Equivalents	Non-Voting Common Stock Equivalents Capital Raise	Nonvoting Common Stock	Nonvoting Common Stock Share Repurchase Program	Private Capital	Pacific Western Bank	Preferred Stock	Common Stock Voting Common Stock	Common Stock Voting Common Stock Capital Raise	Common Stock Class B Non-Voting	Common Stock Non-Voting Common Stock Equivalents	Common Stock Private Capital Voting Common Stock	Common Stock Private Capital Non-Voting Common Stock Equivalents	Common Stock Pacific Western Bank Voting Common Stock	Common Stock Pacific Western Bank Class B Non-Voting	Additional Paid-in Capital	Additional Paid-in Capital Share Repurchase Program	Additional Paid-in Capital Dividend Reinvestment Plan	Additional Paid-in Capital Private Capital	Additional Paid-in Capital Pacific Western Bank	Retained Earnings	Accumulated Other Comprehensive (Loss) Income
Beginning balance at Dec. 31, 2022	$ 3,950,531,000													$ 1,230,000								$ 2,821,064,000					$ 1,420,624,000	$ (790,903,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	(1,899,137,000)																										(1,899,137,000)
OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment and Tax	358,789,000																											358,789,000
Shares Granted, Value, Share-Based Payment Arrangement, after Forfeiture	28,697,000													0								28,697,000
Restricted Stock Award, Forfeitures	(5,419,000)																					(5,419,000)
Dividends, Common Stock, Cash	(48,881,000)																					(48,881,000)
Proceeds from Subordinated Notes Offering													$ 0
Common stock ($0.01 par value, 158,557,735 shares issued and 158,346,529 outstanding at December 31, 2024 ; 157,651,752 shares issued and 156,790,349 outstanding at December 31, 2023)	382,900,000											$ 663,004,000								$ 130,000	$ 5,000					$ 662,869,000
Proceeds from Issuance of Private Placement											$ 382,900,000							$ 217,000	$ 108,000						$ 382,575,000
Dividends, Preferred Stock	$ (39,788,000)																										(39,788,000)
Preferred Stock, Dividends Per Share, Declared	$ 1.9380
Dividends declared per share (usd per share)	$ 0.53
Stock Issued During Period, Value, Stock Options Exercised								10,829,990							21,690,334					(57,157,632)	(477,321)
Ending balance at Dec. 31, 2023	$ 3,390,765,000												498,516,000	1,577,000								3,840,974,000					(518,301,000)	(432,114,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Shares, Issued, Acquisitions							(10,829,990)
Net Income	126,888,000																										126,888,000
OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment and Tax	77,334,000																											77,334,000
Shares Granted, Value, Share-Based Payment Arrangement, after Forfeiture	15,448,000													(1,000)								15,449,000
Restricted Stock Award, Forfeitures	(2,708,000)																					(2,708,000)
Dividends, Common Stock, Cash	(68,298,000)																					(68,298,000)
Common stock ($0.01 par value, 158,557,735 shares issued and 158,346,529 outstanding at December 31, 2024 ; 157,651,752 shares issued and 156,790,349 outstanding at December 31, 2023)	0
Proceeds from Issuance of Private Placement											$ 0
Conversion of Stock, Amount Issued				$ (10,000)			$ (10,000)
Stock Repurchased During Period, Value																						308,000
Dividends, Preferred Stock	$ (39,788,000)																										(39,788,000)
Preferred Stock, Dividends Per Share, Declared	$ 1.9380
Dividends declared per share (usd per share)	$ 0.40
Ending balance at Dec. 31, 2024	$ 3,499,949,000												498,516,000	1,586,000		$ 5,000	$ 98,000					3,785,725,000					(431,201,000)	(354,780,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Shares, Issued, Acquisitions	(158,557,735)					(477,321)	(9,790,600)		(9,790,600)
Net Income	$ 228,973,000																										228,973,000
OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment and Tax	85,519,000																											85,519,000
Shares Granted, Value, Share-Based Payment Arrangement, after Forfeiture	23,352,000													3,000								23,349,000
Restricted Stock Award, Forfeitures	(3,714,000)																					(3,714,000)
Stock Issued During Period, Value, Dividend Reinvestment Plan			$ 282,000																					$ 282,000
Dividends, Common Stock, Cash	(65,646,000)																					(65,646,000)
Common stock ($0.01 par value, 158,557,735 shares issued and 158,346,529 outstanding at December 31, 2024 ; 157,651,752 shares issued and 156,790,349 outstanding at December 31, 2023)	0
Conversion of Stock, Amount Issued				(47,000)			$ (47,000)
Conversion of Voting Common Stock to Non-Voting Common Stock Equivalents				$ (11,000)			$ 11,000
Stock Repurchased During Period, Value		$ 187,727,000			$ 125,000					$ 12,000													$ 187,590,000
Dividends, Preferred Stock	$ (39,788,000)																										(39,788,000)
Preferred Stock, Dividends Per Share, Declared	$ 1.9380
Dividends declared per share (usd per share)	$ 0.40
Ending balance at Dec. 31, 2025	$ 3,541,277,000												$ 498,516,000	$ 1,500,000		$ 5,000	$ 50,000					$ 3,552,483,000					$ (242,016,000)	$ (269,261,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Shares, Issued, Acquisitions	(150,039,018)					(477,321)	(5,017,064)		(5,017,064)