XML 51 R34.htm IDEA: XBRL DOCUMENT
v3.20.4

Valuation and Qualifying Accounts (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2020
Receivables [Abstract] |
Schedule of Valuation and Qualifying Accounts | Valuation and qualifying accounts included the following:
(in thousands) | Balance Beginning of Year |  | Net Charged to Costs and Expenses |  | Translations, Reclassifications and Acquisitions |  | Net Write-Offs or Discounts Taken |  | Balance End of Year
2020 |  |  |  |  |  |  |  |  |  |  |
Reserve for sales discounts | $ | 16,883 |  |  | $ | 93,398 |  |  |  | $ | 15 |  |  |  | $ | (96,747) |  |  | $ | 13,549 |
Reserve for inventory obsolescence | 8,233 |  |  | 4,609 |  |  |  | 1,471 |  |  |  | (2,286) |  |  | 12,027 |
Reserve for warranty | 10,249 |  |  | 8,466 |  |  |  | 247 |  |  |  | (9,866) |  |  | 9,096 |
2019 |  |  |  |  |  |  |  |  |  |  |
Reserve for sales discounts | $ | 18,123 |  |  | $ | 91,962 |  |  |  | $ | 39 |  |  |  | $ | (93,241) |  |  | $ | 16,883 |
Reserve for inventory obsolescence | 7,194 |  |  | 5,711 |  |  |  | 6,467 |  |  |  | (11,139) |  |  | 8,233 |
Reserve for warranty | 4,992 |  |  | 8,273 |  |  |  | 4,343 |  |  |  | (7,359) |  |  | 10,249 |
2018 |  |  |  |  |  |  |  |  |  |  |
Reserve for sales discounts | $ | 15,652 |  |  | $ | 91,082 |  |  |  | $ | (48) |  |  |  | $ | (88,563) |  |  | $ | 18,123 |
Reserve for inventory obsolescence | 6,932 |  |  | 3,773 |  |  |  | (116) |  |  |  | (3,395) |  |  | 7,194 |
Reserve for warranty | 5,335 |  |  | 5,815 |  |  |  | (144) |  |  |  | (6,014) |  |  | 4,992 |

X
- Definition Schedule Of Valuation And Qualifying Accounts [Table Text Block] + References No definition available. + Details
Name: | alg_ScheduleOfValuationAndQualifyingAccountsTableTextBlock
Namespace Prefix: | alg_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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