Loans Receivable, Net - Credit Quality Indicators for RRE and Consumer Loans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Credit Quality Indicators By Origination
Gross charge-offs	$ 3,293	$ 2,694
Total	15,518,612		$ 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	0
Gross charge-offs, revolving loans	0
Gross charge-offs	5	0
Term loans originated current fiscal year	34,038		543,469
Term loans originated fiscal year before current fiscal year	594,723		552,748
Term loans originated two years before current fiscal year	540,013		116,810
Term loans originated three years before current fiscal year	112,360		45,055
Term loans originated four years before current fiscal year	44,792		37,252
Term loans originated five years before current fiscal year	179,783		149,292
Revolving loans	2,694		1,382
Total	1,508,403		1,446,008
Residential real estate | Performing
Credit Quality Indicators By Origination
Term loans originated current fiscal year	34,038		543,023
Term loans originated fiscal year before current fiscal year	592,734		551,756
Term loans originated two years before current fiscal year	539,632		116,543
Term loans originated three years before current fiscal year	112,360		44,604
Term loans originated four years before current fiscal year	44,000		36,993
Term loans originated five years before current fiscal year	176,377		146,318
Revolving loans	2,694		1,382
Total	1,501,835		1,440,619
Residential real estate | 30-89 Days Past Due
Credit Quality Indicators By Origination
Term loans originated current fiscal year	0		446
Term loans originated fiscal year before current fiscal year	1,989		992
Term loans originated two years before current fiscal year	381		136
Term loans originated three years before current fiscal year	0		451
Term loans originated four years before current fiscal year	792		0
Term loans originated five years before current fiscal year	1,316		913
Revolving loans	0		0
Total	4,478		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
Term loans originated fiscal year before current fiscal year	0		0
Term loans originated two years before current fiscal year	0		131
Term loans originated three years before current fiscal year	0		0
Term loans originated four years before current fiscal year	0		259
Term loans originated five years before current fiscal year	2,090		2,061
Revolving loans	0		0
Total	2,090		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	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	0
Gross charge-offs, revolving loans	4
Gross charge-offs	4	0
Term loans originated current fiscal year	0		60
Term loans originated fiscal year before current fiscal year	61		77
Term loans originated two years before current fiscal year	80		82
Term loans originated three years before current fiscal year	26		225
Term loans originated four years before current fiscal year	221		594
Term loans originated five years before current fiscal year	7,196		7,165
Revolving loans	822,260		814,029
Total	829,844		822,232
Home equity | Performing
Credit Quality Indicators By Origination
Term loans originated current fiscal year	0		60
Term loans originated fiscal year before current fiscal year	61		77
Term loans originated two years before current fiscal year	80		82
Term loans originated three years before current fiscal year	26		195
Term loans originated four years before current fiscal year	191		594
Term loans originated five years before current fiscal year	6,893		6,868
Revolving loans	818,067		811,701
Total	825,318		819,577
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	135		131
Revolving loans	2,970		1,152
Total	3,105		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
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		30
Term loans originated four years before current fiscal year	30		0
Term loans originated five years before current fiscal year	168		166
Revolving loans	1,223		1,176
Total	1,421		1,372
Other consumer
Credit Quality Indicators By Origination
Gross charge-offs, originated current fiscal year	2,011
Gross charge-offs, originated fiscal year before current fiscal year	13
Gross charge-offs, originated two years before current fiscal year	47
Gross charge-offs, originated three years before current fiscal year	34
Gross charge-offs, originated four years before current fiscal year	25
Gross charge-offs, prior	35
Gross charge-offs, revolving loans	0
Gross charge-offs	2,165	$ 1,895
Term loans originated current fiscal year	40,877		152,685
Term loans originated fiscal year before current fiscal year	131,626		94,210
Term loans originated two years before current fiscal year	85,679		49,257
Term loans originated three years before current fiscal year	44,976		20,432
Term loans originated four years before current fiscal year	17,849		10,598
Term loans originated five years before current fiscal year	24,027		16,014
Revolving loans	39,208		38,661
Total	384,242		381,857
Other consumer | Performing
Credit Quality Indicators By Origination
Term loans originated current fiscal year	39,490		149,702
Term loans originated fiscal year before current fiscal year	130,497		93,749
Term loans originated two years before current fiscal year	84,915		48,990
Term loans originated three years before current fiscal year	44,746		20,166
Term loans originated four years before current fiscal year	17,487		9,970
Term loans originated five years before current fiscal year	23,266		15,786
Revolving loans	39,057		38,480
Total	379,458		376,843
Other consumer | 30-89 Days Past Due
Credit Quality Indicators By Origination
Term loans originated current fiscal year	1,359		2,825
Term loans originated fiscal year before current fiscal year	875		421
Term loans originated two years before current fiscal year	675		212
Term loans originated three years before current fiscal year	180		96
Term loans originated four years before current fiscal year	205		91
Term loans originated five years before current fiscal year	154		106
Revolving loans	141		179
Total	3,589		3,930
Other consumer | Non-Accrual and 90 Days or More Past Due
Credit Quality Indicators By Origination
Term loans originated current fiscal year	28		158
Term loans originated fiscal year before current fiscal year	254		40
Term loans originated two years before current fiscal year	89		55
Term loans originated three years before current fiscal year	50		170
Term loans originated four years before current fiscal year	157		537
Term loans originated five years before current fiscal year	607		122
Revolving loans	10		2
Total	$ 1,195		$ 1,084