Loans Receivable, Net - Credit Quality Indicators for RRE and Consumer Loans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Credit Quality Indicators By Origination
Gross charge-offs	$ 3,201	$ 3,865	$ 10,284	$ 10,905
Total	16,135,046		16,135,046		$ 15,246,812
Residential real estate
Credit Quality Indicators By Origination
Gross charge-offs, originated current fiscal year			0
Gross charge-offs, originated fiscal year before current fiscal year			5
Gross charge-offs, originated two years before current fiscal year			0
Gross charge-offs, originated three years before current fiscal year			0
Gross charge-offs, originated four years before current fiscal year			0
Gross charge-offs, prior			15
Gross charge-offs, revolving loans			0
Gross charge-offs	0	17	20	17
Term loans originated current fiscal year	163,944		163,944		543,469
Term loans originated fiscal year before current fiscal year	667,972		667,972		552,748
Term loans originated two years before current fiscal year	512,704		512,704		116,810
Term loans originated three years before current fiscal year	101,111		101,111		45,055
Term loans originated four years before current fiscal year	42,480		42,480		37,252
Term loans originated five years before current fiscal year	164,869		164,869		149,292
Revolving loans	697		697		1,382
Total	1,653,777		1,653,777		1,446,008
Residential real estate | Performing
Credit Quality Indicators By Origination
Term loans originated current fiscal year	163,944		163,944		543,023
Term loans originated fiscal year before current fiscal year	667,863		667,863		551,756
Term loans originated two years before current fiscal year	512,704		512,704		116,543
Term loans originated three years before current fiscal year	101,111		101,111		44,604
Term loans originated four years before current fiscal year	42,480		42,480		36,993
Term loans originated five years before current fiscal year	161,427		161,427		146,318
Revolving loans	697		697		1,382
Total	1,650,226		1,650,226		1,440,619
Residential real estate | 30-89 Days Past Due
Credit Quality Indicators By Origination
Term loans originated current fiscal year	0		0		446
Term loans originated fiscal year before current fiscal year	109		109		992
Term loans originated two years before current fiscal year	0		0		136
Term loans originated three years before current fiscal year	0		0		451
Term loans originated four years before current fiscal year	0		0		0
Term loans originated five years before current fiscal year	663		663		913
Revolving loans	0		0		0
Total	772		772		2,938
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		0
Term loans originated fiscal year before current fiscal year	0		0		0
Term loans originated two years before current fiscal year	0		0		131
Term loans originated three years before current fiscal year	0		0		0
Term loans originated four years before current fiscal year	0		0		259
Term loans originated five years before current fiscal year	2,779		2,779		2,061
Revolving loans	0		0		0
Total	2,779		2,779		2,451
Home equity
Credit Quality Indicators By Origination
Gross charge-offs, originated current fiscal year			0
Gross charge-offs, originated fiscal year before current fiscal year			0
Gross charge-offs, originated two years before current fiscal year			48
Gross charge-offs, originated three years before current fiscal year			50
Gross charge-offs, originated four years before current fiscal year			0
Gross charge-offs, prior			4
Gross charge-offs, revolving loans			0
Gross charge-offs	0	0	102	45
Term loans originated current fiscal year	0		0		60
Term loans originated fiscal year before current fiscal year	0		0		77
Term loans originated two years before current fiscal year	0		0		82
Term loans originated three years before current fiscal year	23		23		225
Term loans originated four years before current fiscal year	183		183		594
Term loans originated five years before current fiscal year	6,351		6,351		7,165
Revolving loans	863,406		863,406		814,029
Total	869,963		869,963		822,232
Home equity | Performing
Credit Quality Indicators By Origination
Term loans originated current fiscal year	0		0		60
Term loans originated fiscal year before current fiscal year	0		0		77
Term loans originated two years before current fiscal year	0		0		82
Term loans originated three years before current fiscal year	23		23		195
Term loans originated four years before current fiscal year	183		183		594
Term loans originated five years before current fiscal year	6,139		6,139		6,868
Revolving loans	858,149		858,149		811,701
Total	864,494		864,494		819,577
Home equity | 30-89 Days Past Due
Credit Quality Indicators By Origination
Term loans originated current fiscal year	0		0		0
Term loans originated fiscal year before current fiscal year	0		0		0
Term loans originated two years before current fiscal year	0		0		0
Term loans originated three years before current fiscal year	0		0		0
Term loans originated four years before current fiscal year	0		0		0
Term loans originated five years before current fiscal year	10		10		131
Revolving loans	3,696		3,696		1,152
Total	3,706		3,706		1,283
Home equity | Non-Accrual and 90 Days or More Past Due
Credit Quality Indicators By Origination
Term loans originated current fiscal year	0		0		0
Term loans originated fiscal year before current fiscal year	0		0		0
Term loans originated two years before current fiscal year	0		0		0
Term loans originated three years before current fiscal year	0		0		30
Term loans originated four years before current fiscal year	0		0		0
Term loans originated five years before current fiscal year	202		202		166
Revolving loans	1,561		1,561		1,176
Total	1,763		1,763		1,372
Other consumer
Credit Quality Indicators By Origination
Gross charge-offs, originated current fiscal year			5,766
Gross charge-offs, originated fiscal year before current fiscal year			544
Gross charge-offs, originated two years before current fiscal year			137
Gross charge-offs, originated three years before current fiscal year			76
Gross charge-offs, originated four years before current fiscal year			50
Gross charge-offs, prior			75
Gross charge-offs, revolving loans			0
Gross charge-offs	2,344	$ 2,346	6,648	$ 6,096
Term loans originated current fiscal year	116,739		116,739		152,685
Term loans originated fiscal year before current fiscal year	108,500		108,500		94,210
Term loans originated two years before current fiscal year	67,923		67,923		49,257
Term loans originated three years before current fiscal year	34,794		34,794		20,432
Term loans originated four years before current fiscal year	14,302		14,302		10,598
Term loans originated five years before current fiscal year	19,161		19,161		16,014
Revolving loans	40,656		40,656		38,661
Total	402,075		402,075		381,857
Other consumer | Performing
Credit Quality Indicators By Origination
Term loans originated current fiscal year	114,684		114,684		149,702
Term loans originated fiscal year before current fiscal year	107,466		107,466		93,749
Term loans originated two years before current fiscal year	67,493		67,493		48,990
Term loans originated three years before current fiscal year	34,680		34,680		20,166
Term loans originated four years before current fiscal year	14,101		14,101		9,970
Term loans originated five years before current fiscal year	18,534		18,534		15,786
Revolving loans	40,461		40,461		38,480
Total	397,419		397,419		376,843
Other consumer | 30-89 Days Past Due
Credit Quality Indicators By Origination
Term loans originated current fiscal year	1,956		1,956		2,825
Term loans originated fiscal year before current fiscal year	682		682		421
Term loans originated two years before current fiscal year	384		384		212
Term loans originated three years before current fiscal year	100		100		96
Term loans originated four years before current fiscal year	47		47		91
Term loans originated five years before current fiscal year	77		77		106
Revolving loans	187		187		179
Total	3,433		3,433		3,930
Other consumer | Non-Accrual and 90 Days or More Past Due
Credit Quality Indicators By Origination
Term loans originated current fiscal year	99		99		158
Term loans originated fiscal year before current fiscal year	352		352		40
Term loans originated two years before current fiscal year	46		46		55
Term loans originated three years before current fiscal year	14		14		170
Term loans originated four years before current fiscal year	154		154		537
Term loans originated five years before current fiscal year	550		550		122
Revolving loans	8		8		2
Total	$ 1,223		$ 1,223		$ 1,084