Loans Receivable, Net - Credit Quality Indicators for Commercial Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Credit Quality Indicators By Origination
Total	$ 11,238,048	$ 11,122,696
Commercial real estate
Credit Quality Indicators By Origination
Term loans originated current fiscal year	1,021,389	1,496,094
Term loans originated fiscal year before current fiscal year	1,345,598	1,077,461
Term loans originated two years before current fiscal year	960,097	914,506
Term loans originated three years before current fiscal year	797,895	723,448
Term loans originated four years before current fiscal year	585,881	496,275
Term loans originated five years before current fiscal year	1,741,920	1,488,281
Revolving loans	131,542	119,830
Total	6,584,322	6,315,895
Commercial real estate | Pass
Credit Quality Indicators By Origination
Term loans originated current fiscal year	1,020,590
Term loans originated fiscal year before current fiscal year	1,341,472
Term loans originated two years before current fiscal year	948,682
Term loans originated three years before current fiscal year	757,454
Term loans originated four years before current fiscal year	556,345
Term loans originated five years before current fiscal year	1,691,966
Revolving loans	128,806
Total	6,445,315	6,180,030
Commercial real estate | Special Mention
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	0
Revolving loans	0
Total	0	0
Commercial real estate | Substandard
Credit Quality Indicators By Origination
Term loans originated current fiscal year	799
Term loans originated fiscal year before current fiscal year	4,126
Term loans originated two years before current fiscal year	11,415
Term loans originated three years before current fiscal year	40,441
Term loans originated four years before current fiscal year	29,536
Term loans originated five years before current fiscal year	49,868
Revolving loans	2,735
Total	138,920	135,754
Commercial real estate | Doubtful/ Loss
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	86
Revolving loans	1
Total	87	111
Other commercial
Credit Quality Indicators By Origination
Term loans originated current fiscal year	766,841	1,366,664
Term loans originated fiscal year before current fiscal year	613,476	304,430
Term loans originated two years before current fiscal year	266,759	241,222
Term loans originated three years before current fiscal year	201,000	269,857
Term loans originated four years before current fiscal year	226,830	179,225
Term loans originated five years before current fiscal year	357,769	218,306
Revolving loans	499,744	475,113
Total	2,932,419	3,054,817
Other commercial | Pass
Credit Quality Indicators By Origination
Term loans originated current fiscal year	765,356
Term loans originated fiscal year before current fiscal year	591,994
Term loans originated two years before current fiscal year	258,482
Term loans originated three years before current fiscal year	194,842
Term loans originated four years before current fiscal year	225,041
Term loans originated five years before current fiscal year	341,707
Revolving loans	471,791
Total	2,849,213	2,977,460
Other commercial | Special Mention
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	0
Revolving loans	0
Total	0	32,200
Other commercial | Substandard
Credit Quality Indicators By Origination
Term loans originated current fiscal year	1,485
Term loans originated fiscal year before current fiscal year	21,481
Term loans originated two years before current fiscal year	8,274
Term loans originated three years before current fiscal year	6,157
Term loans originated four years before current fiscal year	1,786
Term loans originated five years before current fiscal year	15,511
Revolving loans	27,936
Total	82,630	44,492
Other commercial | Doubtful/ Loss
Credit Quality Indicators By Origination
Term loans originated current fiscal year	0
Term loans originated fiscal year before current fiscal year	1
Term loans originated two years before current fiscal year	3
Term loans originated three years before current fiscal year	1
Term loans originated four years before current fiscal year	3
Term loans originated five years before current fiscal year	551
Revolving loans	17
Total	$ 576	$ 665