Name:	argo_NetSupplementaryInsuranceInformationAmortizationDeferralOfDeferredPolicyAcquisitionCosts
Namespace Prefix:	argo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Other Underwriting Acquisition And Insurance Expenses

No definition available.

Name:	argo_OtherUnderwritingAcquisitionAndInsuranceExpenses
Namespace Prefix:	argo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Costs incurred during the period, such as those relating to general administration and policy maintenance that do not vary with and are not primarily related to the acquisition or renewal of insurance contracts, excluding amortization of deferred acquisition costs.

No definition available.

Name:	argo_UnderwritingAcquisitionAndInsuranceExpenseGross
Namespace Prefix:	argo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Costs incurred during the period related to selling the Company's products and services including the amortization of deferred policy acquisition costs charged to expense in the period, as well as other costs incurred during the period, such as those relating to general administration and policy maintenance.

No definition available.

Name:	argo_UnderwritingAcquisitionAndInsuranceExpenses
Namespace Prefix:	argo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Underwriting, Acquisition and Insurance Expenses

No definition available.

Name:	argo_UnderwritingAcquisitionAndInsuranceExpensesAbstract
Namespace Prefix:	argo_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The adjustment that represents the periodic charge against earnings to reduce the value of business acquired (VOBA) over the expected life of the underlying insurance contracts. VOBA reflects the estimated fair value of a life insurance business in force and represents the portion of the cost to acquire the business that is allocated to the value of the right to receive future cash flows from insurance contracts existing at the date of acquisition. Such value is the present value of the actuarially determined projected cash flows for the acquired policies. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-28

Name:	us-gaap_AmortizationOfValueOfBusinessAcquiredVOBA
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of fees incurred for commissions on mutual funds and insurance products.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(14))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1