Loans Receivable, Net - Credit Quality Indicators for RRE and Consumer Loans (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Credit Quality Indicators By Origination
Gross Charge-Offs	$ 4,295	$ 3,293
Total	16,732,502		$ 16,198,082
Residential real estate
Credit Quality Indicators By Origination
Gross Charge-Offs, originated current fiscal year	0		0
Gross Charge-Offs, originated fiscal year before current fiscal year	0		5
Gross Charge-Offs, originated two years before current fiscal year	0		0
Gross Charge-Offs, originated three years before current fiscal year	0		0
Gross Charge-Offs, originated four years before current fiscal year	0		0
Gross Charge-Offs, Prior	0		15
Gross Charge-Offs, Revolving loans	0		0
Gross Charge-Offs	0	5	20
Term loans originated current fiscal year	19,177		234,568
Term loans originated fiscal year before current fiscal year	274,053		673,782
Term loans originated two years before current fiscal year	680,095		495,645
Term loans originated three years before current fiscal year	487,436		99,199
Term loans originated four years before current fiscal year	97,272		42,054
Term loans originated five years before current fiscal year	194,211		158,828
Revolving loans	270		468
Total	1,752,514		1,704,544
Residential real estate | Performing
Credit Quality Indicators By Origination
Term loans originated current fiscal year	19,177		233,753
Term loans originated fiscal year before current fiscal year	272,755		671,196
Term loans originated two years before current fiscal year	675,305		495,645
Term loans originated three years before current fiscal year	487,070		99,199
Term loans originated four years before current fiscal year	97,094		42,054
Term loans originated five years before current fiscal year	189,194		153,489
Revolving loans	270		468
Total	1,740,865		1,695,804
Residential real estate | 30-89 Days Past Due
Credit Quality Indicators By Origination
Term loans originated current fiscal year	0		815
Term loans originated fiscal year before current fiscal year	1,298		2,586
Term loans originated two years before current fiscal year	4,790		0
Term loans originated three years before current fiscal year	366		0
Term loans originated four years before current fiscal year	178		0
Term loans originated five years before current fiscal year	2,288		2,670
Revolving loans	0		0
Total	8,920		6,071
Residential real estate | Non-Accrual and 90 Days or More Past Due
Credit Quality Indicators By Origination
Term loans originated current fiscal year	0		0
Term loans originated fiscal year before current fiscal year	0		0
Term loans originated two years before current fiscal year	0		0
Term loans originated three years before current fiscal year	0		0
Term loans originated four years before current fiscal year	0		0
Term loans originated five years before current fiscal year	2,729		2,669
Revolving loans	0		0
Total	2,729		2,669
Home equity
Credit Quality Indicators By Origination
Gross Charge-Offs, originated current fiscal year	0		0
Gross Charge-Offs, originated fiscal year before current fiscal year	15		0
Gross Charge-Offs, originated two years before current fiscal year	0		48
Gross Charge-Offs, originated three years before current fiscal year	0		50
Gross Charge-Offs, originated four years before current fiscal year	0		0
Gross Charge-Offs, Prior	10		31
Gross Charge-Offs, Revolving loans	0		0
Gross Charge-Offs	25	4	129
Term loans originated current fiscal year	0		0
Term loans originated fiscal year before current fiscal year	80		20
Term loans originated two years before current fiscal year	0		0
Term loans originated three years before current fiscal year	132		21
Term loans originated four years before current fiscal year	19		178
Term loans originated five years before current fiscal year	5,285		5,492
Revolving loans	877,546		882,302
Total	883,062		888,013
Home equity | Performing
Credit Quality Indicators By Origination
Term loans originated current fiscal year	0		0
Term loans originated fiscal year before current fiscal year	80		20
Term loans originated two years before current fiscal year	0		0
Term loans originated three years before current fiscal year	132		21
Term loans originated four years before current fiscal year	19		178
Term loans originated five years before current fiscal year	5,195		5,277
Revolving loans	871,986		875,735
Total	877,412		881,231
Home equity | 30-89 Days Past Due
Credit Quality Indicators By Origination
Term loans originated current fiscal year	0		0
Term loans originated fiscal year before current fiscal year	0		0
Term loans originated two years before current fiscal year	0		0
Term loans originated three years before current fiscal year	0		0
Term loans originated four years before current fiscal year	0		0
Term loans originated five years before current fiscal year	10		11
Revolving loans	3,680		4,522
Total	3,690		4,533
Home equity | Non-Accrual and 90 Days or More Past Due
Credit Quality Indicators By Origination
Term loans originated current fiscal year	0		0
Term loans originated fiscal year before current fiscal year	0		0
Term loans originated two years before current fiscal year	0		0
Term loans originated three years before current fiscal year	0		0
Term loans originated four years before current fiscal year	0		0
Term loans originated five years before current fiscal year	80		204
Revolving loans	1,880		2,045
Total	1,960		2,249
Other consumer
Credit Quality Indicators By Origination
Gross Charge-Offs, originated current fiscal year	2,016		7,801
Gross Charge-Offs, originated fiscal year before current fiscal year	95		715
Gross Charge-Offs, originated two years before current fiscal year	136		170
Gross Charge-Offs, originated three years before current fiscal year	30		85
Gross Charge-Offs, originated four years before current fiscal year	22		73
Gross Charge-Offs, Prior	39		131
Gross Charge-Offs, Revolving loans	0		0
Gross Charge-Offs	2,338	$ 2,165	8,975
Term loans originated current fiscal year	34,356		139,295
Term loans originated fiscal year before current fiscal year	120,609		98,630
Term loans originated two years before current fiscal year	88,996		62,961
Term loans originated three years before current fiscal year	57,852		29,143
Term loans originated four years before current fiscal year	24,906		12,335
Term loans originated five years before current fiscal year	26,798		17,314
Revolving loans	40,532		40,678
Total	394,049		400,356
Other consumer | Performing
Credit Quality Indicators By Origination
Term loans originated current fiscal year	32,449		137,035
Term loans originated fiscal year before current fiscal year	120,230		97,536
Term loans originated two years before current fiscal year	88,326		62,107
Term loans originated three years before current fiscal year	57,040		29,012
Term loans originated four years before current fiscal year	24,797		12,279
Term loans originated five years before current fiscal year	26,340		16,664
Revolving loans	40,027		39,489
Total	389,209		394,122
Other consumer | 30-89 Days Past Due
Credit Quality Indicators By Origination
Term loans originated current fiscal year	1,907		2,079
Term loans originated fiscal year before current fiscal year	244		870
Term loans originated two years before current fiscal year	487		805
Term loans originated three years before current fiscal year	658		119
Term loans originated four years before current fiscal year	96		43
Term loans originated five years before current fiscal year	182		173
Revolving loans	503		1,182
Total	4,077		5,271
Other consumer | Non-Accrual and 90 Days or More Past Due
Credit Quality Indicators By Origination
Term loans originated current fiscal year	0		181
Term loans originated fiscal year before current fiscal year	135		224
Term loans originated two years before current fiscal year	183		49
Term loans originated three years before current fiscal year	154		12
Term loans originated four years before current fiscal year	13		13
Term loans originated five years before current fiscal year	276		477
Revolving loans	2		7
Total	$ 763		$ 963