Loans Receivable, Net - Credit Quality Indicators for RRE and Consumer Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Credit Quality Indicators By Origination
Total	$ 11,238,048	$ 11,122,696
Residential real estate
Credit Quality Indicators By Origination
Term loans originated current fiscal year	121,489	208,679
Term loans originated fiscal year before current fiscal year	205,741	181,924
Term loans originated two years before current fiscal year	101,077	100,273
Term loans originated three years before current fiscal year	67,729	76,394
Term loans originated four years before current fiscal year	58,675	53,819
Term loans originated five years before current fiscal year	177,776	179,085
Revolving loans	2,351	2,334
Total	734,838	802,508
Residential real estate | Performing
Credit Quality Indicators By Origination
Term loans originated current fiscal year	121,489
Term loans originated fiscal year before current fiscal year	205,741
Term loans originated two years before current fiscal year	101,077
Term loans originated three years before current fiscal year	67,445
Term loans originated four years before current fiscal year	58,495
Term loans originated five years before current fiscal year	174,486
Revolving loans	2,351
Total	731,084	791,529
Residential real estate | 30-89 Days Past Due
Credit Quality Indicators By Origination
Term loans originated current fiscal year	0
Term loans originated fiscal year before current fiscal year	0
Term loans originated two years before current fiscal year	0
Term loans originated three years before current fiscal year	52
Term loans originated four years before current fiscal year	0
Term loans originated five years before current fiscal year	181
Revolving loans	0
Total	233	6,642
Residential real estate | Non-Accrual and 90 Days or More Past Due
Credit Quality Indicators By Origination
Term loans originated current fiscal year	0
Term loans originated fiscal year before current fiscal year	0
Term loans originated two years before current fiscal year	0
Term loans originated three years before current fiscal year	232
Term loans originated four years before current fiscal year	180
Term loans originated five years before current fiscal year	3,109
Revolving loans	0
Total	3,521	4,337
Home equity
Credit Quality Indicators By Origination
Term loans originated current fiscal year	47	89
Term loans originated fiscal year before current fiscal year	69	807
Term loans originated two years before current fiscal year	607	1,782
Term loans originated three years before current fiscal year	1,093	1,452
Term loans originated four years before current fiscal year	852	1,016
Term loans originated five years before current fiscal year	11,616	14,025
Revolving loans	634,516	617,234
Total	648,800	636,405
Home equity | Performing
Credit Quality Indicators By Origination
Term loans originated current fiscal year	47
Term loans originated fiscal year before current fiscal year	69
Term loans originated two years before current fiscal year	573
Term loans originated three years before current fiscal year	1,093
Term loans originated four years before current fiscal year	827
Term loans originated five years before current fiscal year	11,068
Revolving loans	630,330
Total	644,007	630,671
Home equity | 30-89 Days Past Due
Credit Quality Indicators By Origination
Term loans originated current fiscal year	0
Term loans originated fiscal year before current fiscal year	0
Term loans originated two years before current fiscal year	0
Term loans originated three years before current fiscal year	0
Term loans originated four years before current fiscal year	0
Term loans originated five years before current fiscal year	24
Revolving loans	1,947
Total	1,971	2,886
Home equity | Non-Accrual and 90 Days or More Past Due
Credit Quality Indicators By Origination
Term loans originated current fiscal year	0
Term loans originated fiscal year before current fiscal year	0
Term loans originated two years before current fiscal year	34
Term loans originated three years before current fiscal year	0
Term loans originated four years before current fiscal year	25
Term loans originated five years before current fiscal year	524
Revolving loans	2,239
Total	2,822	2,848
Other consumer
Credit Quality Indicators By Origination
Term loans originated current fiscal year	98,287	131,302
Term loans originated fiscal year before current fiscal year	100,652	66,327
Term loans originated two years before current fiscal year	48,832	42,827
Term loans originated three years before current fiscal year	27,480	16,287
Term loans originated four years before current fiscal year	11,159	10,519
Term loans originated five years before current fiscal year	22,098	18,692
Revolving loans	29,161	27,117
Total	337,669	313,071
Other consumer | Performing
Credit Quality Indicators By Origination
Term loans originated current fiscal year	98,258
Term loans originated fiscal year before current fiscal year	100,363
Term loans originated two years before current fiscal year	48,485
Term loans originated three years before current fiscal year	27,170
Term loans originated four years before current fiscal year	11,115
Term loans originated five years before current fiscal year	20,568
Revolving loans	29,098
Total	335,057	310,225
Other consumer | 30-89 Days Past Due
Credit Quality Indicators By Origination
Term loans originated current fiscal year	29
Term loans originated fiscal year before current fiscal year	247
Term loans originated two years before current fiscal year	104
Term loans originated three years before current fiscal year	99
Term loans originated four years before current fiscal year	37
Term loans originated five years before current fiscal year	1,308
Revolving loans	61
Total	1,885	2,192
Other consumer | Non-Accrual and 90 Days or More Past Due
Credit Quality Indicators By Origination
Term loans originated current fiscal year	0
Term loans originated fiscal year before current fiscal year	42
Term loans originated two years before current fiscal year	243
Term loans originated three years before current fiscal year	211
Term loans originated four years before current fiscal year	7
Term loans originated five years before current fiscal year	222
Revolving loans	2
Total	$ 727	$ 654