XML 30 R15.htm IDEA: XBRL DOCUMENT
v3.20.4

Line of Credit | 12 Months Ended
--- | ---
Dec. 31, 2020
Text Block [Abstract] |
Line of Credit |
8. | Line of Credit
The Company has an agreement providing for a line of credit in the maximum amount of $20.0 million with Frost Bank. The agreement expires in December 2022. Under the agreement, advances may be made either in the form of loans or letters of credit. Borrowings under the agreement accrue at interest rates based upon prime rate, LIBOR or equivalent. Under the agreement, the Company pays a fee of 0.25% on the unused portion of the loan in arrears quarterly, or a fee of $50,000 annually, assuming the line of credit is not used during the calendar year. The line of credit is unsecured. No borrowings or letters of credit were outstanding under the line of credit arrangement at December 31, 2020 or 2019.

X
- Definition Line of credit text block. + References No definition available. + Details
Name: | amsf_LineOfCreditTextBlock
Namespace Prefix: | amsf_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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