XML 60 R47.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Inventories (Inventory reserve) (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2021 | Dec. 31, 2020
Inventory Valuation Reserves Increase (Decrease) [Roll Forward] |  |
Balance at beginning of period | $ 144,942 | $ 66,075
Charged to expense | 8,096 | 100,794
Deductions or other | (90,153) | (21,927)
Balance at end of period | $ 62,885 | $ 144,942

X
- Definition Inventory Valuation Reserves, Deduction and Other Reserve Decrease + References No definition available. + Details
Name: | fet_InventoryValuationReservesDeductionAndOtherReserveDecrease
Namespace Prefix: | fet_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Inventory Valuation Reserves Increase (Decrease) [Roll Forward] + References No definition available. + Details
Name: | fet_InventoryValuationReservesIncreaseDecreaseRollForward
Namespace Prefix: | fet_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of valuation reserve for inventory. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 330 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SAB TOPIC 5.BB) -URI http://asc.fasb.org/extlink&oid=27011343&loc=d3e100047-122729 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.6(a)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_InventoryValuationReserves
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of loss from reductions in inventory due to subsequent measurement adjustments, including, but not limited to, physical deterioration, obsolescence, or changes in price levels. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 330 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=116847112&loc=d3e4542-108314 + Details
Name: | us-gaap_InventoryWriteDown
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration