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

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

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

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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.

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Weighted average interest rate of debt outstanding.

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Fixed interest rate related to the interest rate derivative.

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

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Amount of liability hedged in fair value hedging relationship.

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Amount of the cost of borrowed funds accounted for as interest expense for debt.

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Amount of cash paid for interest, including, but not limited to, capitalized interest and payment to settle zero-coupon bond attributable to accreted interest of debt discount and debt instrument with insignificant coupon interest rate in relation to effective interest rate of borrowing attributable to accreted interest of debt discount; classified as operating and investing activities.

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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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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.

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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.

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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.

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The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

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Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

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

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Debt (Narrative) (Details) - USD ($) $ in Millions		3 Months Ended	8 Months Ended	12 Months Ended
Debt (Narrative) (Details) - USD ($) $ in Millions	Apr. 01, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 23, 2019	Jun. 15, 2018	May 18, 2018	May 11, 2018	May 12, 2017	Aug. 14, 2013
Debt Instrument
Interest expense on debt				$ 17.6	$ 9.5	$ 2.3
Repayments of debt, principal				22.9	15.4	365.0
Debt		$ 283.5	$ 192.7	283.5	192.7
Draw down of debt and revolving line of credit				206.4	84.1	376.0
Interest paid				16.3	8.8	1.4
WTM Bank Facility
Debt Instrument
Total commitment under revolving credit facility												$ 425.0
Interest expense on debt				0.3	0.6
NSM Holding Co LLC
Debt Instrument
Debt instrument at face value										$ 100.0
Debt		219.2	178.5	219.2	178.5
NSM Holding Co LLC \| NSM Bank Facility
Debt Instrument
Total commitment under revolving credit facility										234.0
Kudu \| Kudu Debt
Debt Instrument
Total commitment under revolving credit facility							$ 125.0
MediaAlpha
Debt Instrument
Debt		0.0	14.2	0.0	14.2
MediaAlpha \| MediaAlpha Bank Facility
Debt Instrument
Total commitment under revolving credit facility											$ 20.0
Interest expense on debt					1.2	1.0
Debt instrument at face value		0.0	14.3	0.0	14.3
Debt		$ 0.0	$ 14.2	$ 0.0	$ 14.2
Effective yield (as a percent)			7.10%		7.10%
Draw down of debt and revolving line of credit					$ 3.0	20.0
MediaAlpha \| Previous MediaAlpha Bank Facility
Debt Instrument
Total commitment under revolving credit facility			$ 20.0		20.0
Repayments of debt, principal						12.9
Term Loan \| Other Operations
Debt Instrument
Debt instrument at face value			11.3		11.3
Term Loan \| NSM Holding Co LLC \| NSM Bank Facility
Debt Instrument
Total commitment under revolving credit facility										224.0
Debt instrument at face value		$ 221.3	180.4	$ 221.3	180.4				$ 51.0
Repayments of debt, principal			0.8	2.0
Proceeds from borrowings				42.9
Debt		$ 217.4	$ 176.6	$ 217.4	$ 176.6
Effective yield (as a percent)		7.50%	7.40%	7.50%	7.40%
Term Loan \| NSM Holding Co LLC \| Other NSM
Debt Instrument
Debt instrument at face value		$ 1.8		$ 1.8
Debt		$ 1.8	$ 1.9	$ 1.8	$ 1.9
Effective yield (as a percent)		3.00%	2.20%	3.00%	2.20%
Term Loan \| Kudu \| Kudu Debt
Debt Instrument
Total commitment under revolving credit facility							57.0
Debt instrument at face value		$ 57.0		$ 57.0
Term Loan \| MediaAlpha \| MediaAlpha Bank Facility
Debt Instrument
Total commitment under revolving credit facility			$ 18.4		$ 18.4
Debt instrument at face value			14.3		14.3
Repayments of debt, principal					3.6	2.1
Delayed Draw Term Loans \| Other Operations
Debt Instrument
Debt instrument at face value			3.0		3.0
Delayed Draw Term Loans \| Kudu \| Kudu Debt
Debt Instrument
Total commitment under revolving credit facility							63.0
Revolving Credit Facility \| Other Operations
Debt Instrument
Debt instrument at face value			2.0		2.0
Revolving Credit Facility \| NSM Holding Co LLC \| NSM Bank Facility
Debt Instrument
Total commitment under revolving credit facility										$ 10.0
Repayments of debt, principal			2.0	6.5
Proceeds from borrowings				$ 6.5
Revolving Credit Facility \| Kudu \| Kudu Debt
Debt Instrument
Total commitment under revolving credit facility							5.0
Current borrowing capacity							$ 57.0
Revolving Credit Facility \| MediaAlpha \| MediaAlpha Bank Facility
Debt Instrument
Amount outstanding			$ 10.0		10.0
Repayments of debt, principal					9.0
Draw down of debt and revolving line of credit						6.0
London Interbank Offered Rate (LIBOR) \| Term Loan \| Minimum \| NSM Holding Co LLC \| NSM Bank Facility
Debt Instrument
Basis spread on variable rate		4.25%	4.25%
London Interbank Offered Rate (LIBOR) \| Term Loan \| Maximum \| NSM Holding Co LLC \| NSM Bank Facility
Debt Instrument
Basis spread on variable rate		4.75%	4.75%
London Interbank Offered Rate (LIBOR) \| Line of Credit \| Kudu \| Kudu Debt
Debt Instrument
Basis spread on variable rate				1.00%
London Interbank Offered Rate (LIBOR) \| Line of Credit \| Minimum \| Kudu \| Kudu Debt
Debt Instrument
Basis spread on variable rate		5.50%
London Interbank Offered Rate (LIBOR) \| Line of Credit \| Maximum \| Kudu \| Kudu Debt
Debt Instrument
Basis spread on variable rate		6.25%
Prime Rate \| Term Loan \| Minimum \| NSM Holding Co LLC \| NSM Bank Facility
Debt Instrument
Basis spread on variable rate		3.25%	3.25%
Prime Rate \| Term Loan \| Maximum \| NSM Holding Co LLC \| NSM Bank Facility
Debt Instrument
Basis spread on variable rate		3.75%	3.75%
Prime Rate \| Line of Credit \| Minimum \| Kudu \| Kudu Debt
Debt Instrument
Basis spread on variable rate		4.50%
Prime Rate \| Line of Credit \| Maximum \| Kudu \| Kudu Debt
Debt Instrument
Basis spread on variable rate		5.25%
Interest Rate Swap \| NSM Holding Co LLC
Debt Instrument
Fixed interest rate		2.97%		2.97%
Variable interest rate		1.71%		1.71%
Interest Rate Swap \| Term Loan \| NSM Holding Co LLC \| NSM Bank Facility
Debt Instrument
Total commitment under revolving credit facility								$ 151.0
Hedged liability, fair value hedge								$ 151.0
Fixed interest rate		2.97%		2.97%
Debt		$ 148.7		$ 148.7
Debt, weighted average interest rate		7.06%		7.06%
Embrace Pet Insurance \| NSM Holding Co LLC
Debt Instrument
Proceeds from borrowings	$ 20.4
Embrace Pet Insurance \| Term Loan \| NSM Holding Co LLC \| NSM Bank Facility
Debt Instrument
Proceeds from borrowings				$ 20.4
NSM Holding Co LLC
Debt Instrument
Interest expense on debt				16.7	$ 8.0	$ 0.0
Designated as Hedging Instrument \| Interest Rate Swap \| Term Loan \| NSM Holding Co LLC \| NSM Bank Facility
Debt Instrument
Debt		$ 148.7		$ 148.7
Debt, weighted average interest rate		7.47%		7.47%
Not Designated as Hedging Instrument \| Interest Rate Swap \| Term Loan \| NSM Holding Co LLC \| NSM Bank Facility
Debt Instrument
Debt		$ 72.6		$ 72.6
Effective yield (as a percent)		6.21%		6.21%
Renewal Rights \| Term Loan \| NSM Holding Co LLC \| NSM Bank Facility
Debt Instrument
Proceeds from borrowings				$ 22.5