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Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Oct. 19, 2020	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Commitments And Contingencies [Line Items]
Allowance for credit loss		$ 46,365	$ 46,316	$ 46,365	$ 46,316	$ 49,828	$ 52,420	$ 43,356	$ 30,482
Statute of limitations period	3 years
New York [Member]
Commitments And Contingencies [Line Items]
Statute of limitations period	6 years
Unfunded Commitments [Member]
Commitments And Contingencies [Line Items]
Credit loss (benefit) expense		(764)	$ 5	(1,000)	$ 498
Unfunded Commitments [Member] | Other Liabilities [Member]
Commitments And Contingencies [Line Items]
Allowance for credit loss		$ 2,100		$ 2,100			$ 3,100

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Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(7)(2))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121599878&loc=SL82895884-210446

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
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-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919249-210447

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
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