Financing agreement maturity period.

No definition available.

Name:	fath_FinancingAgreementMaturityPeriod
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Balance Type:	na
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- Definition

Financing annual rate.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Financing fee.

+ References

No definition available.

+ Details

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Namespace Prefix:	fath_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Financing payments.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

- Definition

Financing payments recognized in assets.

+ References

No definition available.

+ Details

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Namespace Prefix:	fath_
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Balance Type:	debit
Period Type:	instant

- Definition

Financing payments recognized in liabilities.

+ References

No definition available.

+ Details

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Namespace Prefix:	fath_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Increase decrease in term loan facility and revolving credit facility.

+ References

No definition available.

+ Details

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Namespace Prefix:	fath_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Interest on debt increments period.

+ References

No definition available.

+ Details

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Namespace Prefix:	fath_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of amortization expense attributable to debt issuance costs.

+ References

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

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+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Balance Type:	debit
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- Definition

The expense in the period incurred with respect to protection provided by insurance entities against risks other than risks associated with production (which are allocated to cost of sales).

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- Definition

Interest and debt related expenses associated with nonoperating financing activities of the entity.

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Maturity date of long-term debt, in YYYY-MM-DD format.

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Period Type:	instant

- Details

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- Details

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Balance Type:
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- Details

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Balance Type:
Period Type:

- Details

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Balance Type:
Period Type:

- Details

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Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Debt - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Dec. 31, 2021	Mar. 31, 2022	Mar. 31, 2021	Dec. 23, 2021
Debt Instrument [Line Items]
Debt issuance costs gross				$ 1,828
Long term debt date of maturity				Dec. 31, 2026
Interest on debt increments period		90 days
Interest and debt expense		$ 1,473	$ 2,114
Amortization of debt issuance costs		100	$ 96
Financing agreement maturity period	10 months
Financing payments	$ 3,001
Financing fee	$ 35
Financing annual rate	2.57%
SG&A Expenses [Member]
Debt Instrument [Line Items]
Insurance expense		842
Prepaid Assets [Member]
Debt Instrument [Line Items]
Financing payments recognized in assets		2,176
Other Current Liabilities [Member]
Debt Instrument [Line Items]
Financing payments recognized in liabilities		2,090
Term Loan [Member]
Debt Instrument [Line Items]
Debt instrument face value				$ 125,000
New Credit Agreement [Member]
Debt Instrument [Line Items]
Increase decrease in term loan facility and revolving credit facility				100,000
Revolving Credit Facility [Member] \| New Credit Agreement [Member]
Debt Instrument [Line Items]
Line of credit maximum borrowing capacity				50,000
Borrowings from credit agreement		$ 22,000
Letter of Credit [Member] \| Revolving Credit Facility [Member] \| New Credit Agreement [Member]
Debt Instrument [Line Items]
Line of credit maximum borrowing capacity				$ 5,000