Segment Information - Information about Company's Segments (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Segment Reporting Information [Line Items]
Net Income (Loss)	$ 701,624	$ 362,174
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues	2,405,397	1,445,061
Previously Reported [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues		1,445,061
Net Income (Loss)		362,174
Revision of Prior Period, Reclassification, Adjustment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues		1,445,061
Net Income (Loss)		362,174
Business Banking [Member]
Segment Reporting Information [Line Items]
Net Income (Loss)	113,251	39,532
Business Banking [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues	273,551	141,346
Business Banking [Member] | Intersegment Activity Eliminated in Consolidated Totals [Member]
Segment Reporting Information [Line Items]
Total Revenues	877	671
Business Banking [Member] | Previously Reported [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues		141,346
Net Income (Loss)		41,111
Business Banking [Member] | Revision of Prior Period, Reclassification, Adjustment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues		141,346
Net Income (Loss)		39,532
Business Banking [Member] | Impact Of Changes [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net Income (Loss)		(1,579)
Commercial Banking [Member]
Segment Reporting Information [Line Items]
Net Income (Loss)	219,979	128,460
Commercial Banking [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues	507,020	278,935
Commercial Banking [Member] | Intersegment Activity Eliminated in Consolidated Totals [Member]
Segment Reporting Information [Line Items]
Total Revenues	10,226	863
Commercial Banking [Member] | Previously Reported [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues		289,372
Net Income (Loss)		144,608
Commercial Banking [Member] | Revision of Prior Period, Reclassification, Adjustment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues		278,935
Net Income (Loss)		128,460
Commercial Banking [Member] | Impact Of Changes [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues		(10,437)
Net Income (Loss)		(16,148)
Commercial Real Estate [Member]
Segment Reporting Information [Line Items]
Net Income (Loss)	80,809	111,246
Commercial Real Estate [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues	225,719	212,524
Commercial Real Estate [Member] | Intersegment Activity Eliminated in Consolidated Totals [Member]
Segment Reporting Information [Line Items]
Total Revenues	289	179
Commercial Real Estate [Member] | Previously Reported [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues		202,087
Net Income (Loss)		97,610
Commercial Real Estate [Member] | Revision of Prior Period, Reclassification, Adjustment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues		212,524
Net Income (Loss)		111,246
Commercial Real Estate [Member] | Impact Of Changes [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues		10,437
Net Income (Loss)		13,636
Discretionary Portfolio [Member]
Segment Reporting Information [Line Items]
Net Income (Loss)	(40,397)	34,685
Discretionary Portfolio [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues	(33,396)	64,727
Discretionary Portfolio [Member] | Intersegment Activity Eliminated in Consolidated Totals [Member]
Segment Reporting Information [Line Items]
Total Revenues	(15,205)	(27,805)
Discretionary Portfolio [Member] | Previously Reported [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues		64,727
Net Income (Loss)		35,385
Discretionary Portfolio [Member] | Revision of Prior Period, Reclassification, Adjustment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues		64,727
Net Income (Loss)		34,685
Discretionary Portfolio [Member] | Impact Of Changes [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net Income (Loss)		(700)
Residential Mortgage Banking [Member]
Segment Reporting Information [Line Items]
Net Income (Loss)	(12,354)	27,114
Residential Mortgage Banking [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues	77,654	137,444
Residential Mortgage Banking [Member] | Intersegment Activity Eliminated in Consolidated Totals [Member]
Segment Reporting Information [Line Items]
Total Revenues	20,472	37,464
Residential Mortgage Banking [Member] | Previously Reported [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues		137,444
Net Income (Loss)		28,964
Residential Mortgage Banking [Member] | Revision of Prior Period, Reclassification, Adjustment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues		137,444
Net Income (Loss)		27,114
Residential Mortgage Banking [Member] | Impact Of Changes [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net Income (Loss)		(1,850)
Retail Banking [Member]
Segment Reporting Information [Line Items]
Net Income (Loss)	316,594	79,082
Retail Banking [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues	831,842	355,148
Retail Banking [Member] | Intersegment Activity Eliminated in Consolidated Totals [Member]
Segment Reporting Information [Line Items]
Total Revenues	(39)	(3)
Retail Banking [Member] | Previously Reported [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues		355,148
Net Income (Loss)		84,164
Retail Banking [Member] | Revision of Prior Period, Reclassification, Adjustment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues		355,148
Net Income (Loss)		79,082
Retail Banking [Member] | Impact Of Changes [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net Income (Loss)		(5,082)
All Other [Member]
Segment Reporting Information [Line Items]
Net Income (Loss)	23,742	(57,945)
All Other [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues	523,007	254,937
All Other [Member] | Intersegment Activity Eliminated in Consolidated Totals [Member]
Segment Reporting Information [Line Items]
Total Revenues	$ (16,620)	(11,369)
All Other [Member] | Previously Reported [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues		254,937
Net Income (Loss)		(69,668)
All Other [Member] | Revision of Prior Period, Reclassification, Adjustment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues		254,937
Net Income (Loss)		(57,945)
All Other [Member] | Impact Of Changes [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net Income (Loss)		$ 11,723