XML 79 R37.htm IDEA: XBRL DOCUMENT
v3.20.2

Interest Receivable (Tables) | 12 Months Ended
--- | ---
Sep. 30, 2020
Receivables [Abstract] |
Schedule of interest receivable | The following table provides a summary of interest receivable by interest-earning asset type.
| September 30, 2020 |  | September 30, 2019
| (In thousands)
Loans receivable | $ | 48,704 |  |  | $ | 41,429 |
Mortgage-backed securities | 3,071 |  |  | 6,107 |
Investment securities | 2,024 |  |  | 1,321 |
| $ | 53,799 |  |  | $ | 48,857 |

X
- References No definition available. + Details
Name: | us-gaap_ReceivablesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Interest Receivable [Table Text Block] + References No definition available. + Details
Name: | wfsl_InterestReceivableTableTextBlock
Namespace Prefix: | wfsl_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration