Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

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-Topic 835
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-Section 45
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-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

+ Details

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- 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.

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- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

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- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

+ Details

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- Definition

Variable interest rate in effect as of the balance sheet date related to the interest rate derivative.

+ References

No definition available.

+ Details

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
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-Subparagraph (SX 210.5-02(22))
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Period Type:	instant

- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

+ Details

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- 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

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

No definition available.

+ Details

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- Definition

Amount of cash outflow for payment of an obligation from a lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
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-Paragraph 15
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- Definition

The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

+ References

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Debt (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Debt (Details) - USD ($) $ in Millions	Jun. 30, 2018	Jun. 30, 2018	Jun. 30, 2017	May 11, 2018	Dec. 31, 2017	Oct. 05, 2017	May 12, 2017	Aug. 14, 2013
Debt Instrument
Total debt	$ 169.6	$ 169.6			$ 23.8
Repayments of debt		6.1	$ 13.3
WTM Bank Facility
Debt Instrument
Total commitment under revolving credit facility								$ 425.0
White Mountains \| WTM Bank Facility
Debt Instrument
Total debt	0.0	0.0			0.0
MediaAlpha
Debt Instrument
Total debt	19.8	19.8			23.8
MediaAlpha \| MediaAlpha Bank Facility
Debt Instrument
Face amount	$ 19.9	$ 19.9			$ 23.9
Effective percentage	6.20%	6.20%			5.60%
Unamortized issuance cost	$ (0.1)	$ (0.1)			$ (0.1)
Total commitment under revolving credit facility						$ 28.4	$ 20.0
Long-term line of credit	19.8	19.8			23.8
Repayment of lines of credit	1.0	2.0
NSM Holding Co LLC
Debt Instrument
Total debt	149.8	149.8			0.0
NSM Holding Co LLC \| NSM Bank Facility
Debt Instrument
Total commitment under revolving credit facility				$ 100.0
Repayment of lines of credit	2.0
Revolving Credit Facility \| MediaAlpha \| MediaAlpha Bank Facility
Debt Instrument
Long-term line of credit	4.0	$ 4.0
Revolving Credit Facility \| NSM Holding Co LLC \| NSM Bank Facility
Debt Instrument
Total commitment under revolving credit facility				10.0
Borrowings under facility				2.0
Term Loan \| MediaAlpha Bank Facility
Debt Instrument
Basis spread on variable rate		1.50%
Term Loan \| MediaAlpha \| MediaAlpha Bank Facility
Debt Instrument
Total commitment under revolving credit facility	18.4	$ 18.4
Long-term line of credit	15.9	15.9
Repayments of debt	0.7	2.0
Term Loan \| NSM Holding Co LLC
Debt Instrument
Total debt	2.3	2.3			0.0
Term Loan \| NSM Holding Co LLC \| NSM Bank Facility
Debt Instrument
Face amount	$ 151.0	$ 151.0			0.0
Effective percentage	8.70%	8.70%
Unamortized issuance cost	$ (3.5)	$ (3.5)			0.0
Long-term line of credit	$ 147.5	$ 147.5		$ 51.0	0.0
Debt, weighted average interest rate, all-in	6.84%	6.84%
Term Loan \| NSM Holding Co LLC \| Ageas Bank Facility
Debt Instrument
Long-term line of credit	$ 2.3	$ 2.3
Line of Credit \| MediaAlpha Bank Facility
Debt Instrument
Basis spread on variable rate		0.25%
Interest Rate Swap \| NSM Holding Co LLC
Debt Instrument
Derivative, fixed interest rate	2.9745%	2.9745%
Derivative, variable interest rate	2.07%	2.07%
Interest Rate Swap \| Term Loan \| NSM Bank Facility
Debt Instrument
Derivative, variable interest rate	2.07325%	2.07325%
Interest Rate Swap \| Term Loan \| NSM Holding Co LLC \| NSM Bank Facility
Debt Instrument
Derivative, fixed interest rate	2.9745%	2.9745%
Debt, weighted average interest rate, all-in	7.47%	7.47%
Reported Value Measurement \| MediaAlpha \| MediaAlpha Bank Facility
Debt Instrument
Total debt	$ 19.8	$ 19.8			$ 23.8
Reported Value Measurement \| NSM Holding Co LLC \| NSM Bank Facility
Debt Instrument
Total debt	$ 147.5	$ 147.5
London Interbank Offered Rate (LIBOR) \| Minimum \| Term Loan \| NSM Holding Co LLC \| NSM Bank Facility
Debt Instrument
Basis spread on variable rate	4.25%	4.25%
London Interbank Offered Rate (LIBOR) \| Maximum \| Term Loan \| NSM Holding Co LLC \| NSM Bank Facility
Debt Instrument
Basis spread on variable rate	4.75%	4.75%
Prime Rate \| Minimum \| Term Loan \| NSM Holding Co LLC \| NSM Bank Facility
Debt Instrument
Basis spread on variable rate	3.25%
Prime Rate \| Maximum \| Term Loan \| NSM Holding Co LLC \| NSM Bank Facility
Debt Instrument
Basis spread on variable rate	3.75%