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Debt - Narrative (Details) £ in Millions |  | 1 Months Ended | 3 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Apr. 07, 2020 USD ($) | Apr. 07, 2020 GBP (£) | Mar. 31, 2007 USD ($) | Mar. 31, 2021 USD ($) credit_facility | Mar. 31, 2021 GBP (£) | Mar. 31, 2020 USD ($) | Mar. 31, 2021 EUR (€) credit_facility | Dec. 31, 2020 USD ($) | Dec. 31, 2019 USD ($) | Jun. 15, 2018 USD ($) | Mar. 31, 2007 EUR (€)
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Total commitment under revolving credit facility | $ 291,400,000 |  |  |  |  | $ 234,000,000.0 |  |  |  |  |
Debt covenant, maximum loan to value percent, period one |  |  |  | 50.00% |  |  | 50.00% |  |  |  |
Debt covenant, maximum loan to value percent, period two |  |  |  | 40.00% |  |  | 40.00% |  |  |  |
Debt covenant, maximum loan to value percent, period three |  |  |  | 25.00% |  |  | 25.00% |  |  |  |
Debt covenant, maximum loan to value percent, period four |  |  |  | 15.00% |  |  | 15.00% |  |  |  |
Debt covenant, maximum loan to value percent, period five |  |  |  | 0.00% |  |  | 0.00% |  |  |  |
Debt covenant, maximum loan to value percent |  |  |  | 29.50% |  |  | 29.50% |  |  |  |
Debt |  |  |  | $ 429,700,000 |  |  |  | $ 376,400,000 |  |  |
Draw down of debt and revolving line of credit |  |  |  | $ 105,300,000 |  | $ 12,000,000.0 |  |  |  |  |
Other |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Secured credit facilities | credit_facility |  |  |  | 2 |  |  | 2 |  |  |  |
Specialty Insurance Distribution (NSM) |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  | $ 272,700,000 |  |  |  | 272,600,000 |  |  |
Weighted Average Interest rate |  |  |  | 8.50% |  | 7.60% | 8.50% |  |  |  |
Specialty Insurance Distribution (NSM) | Term loan - hedged |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Weighted Average Interest rate |  |  |  | 9.20% |  | 8.10% | 9.20% |  |  |  |
Specialty Insurance Distribution (NSM) | Term loan - unhedged |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Weighted Average Interest rate |  |  |  | 7.70% |  | 6.60% | 7.70% |  |  |  |
NSM Bank Facility | Specialty Insurance Distribution (NSM) |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Amount borrowed |  |  |  | $ 277,300,000 |  |  |  |  |  |  |
Percentage of discounted future cash flows |  |  |  | 10.00% | 10.00% |  |  |  |  |  |
Debt |  |  |  | $ 277,300,000 |  | $ 220,700,000 |  | 277,400,000 | $ 221,300,000 |  |
NSM Bank Facility | Term Loan |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  | 271,500,000 |  |  |  | 271,300,000 |  |  |
Amount borrowed |  |  |  | 277,300,000 |  |  |  | 277,400,000 |  |  |
NSM Bank Facility | Term Loan | Specialty Insurance Distribution (NSM) |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Amount borrowed | 276,400,000 |  |  |  |  | 224,000,000.0 |  |  |  |  |
Borrowings | $ 52,400,000 | £ 42.5 |  | 0 |  | 0 |  |  |  |  |
NSM Bank Facility | Term Loan | Specialty Insurance Distribution (NSM) | Interest Rate Swap |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Total commitment under revolving credit facility |  |  |  |  |  |  |  |  |  | $ 151,000,000.0 |
Hedged liability, fair value |  |  |  |  |  |  |  |  |  | $ 151,000,000.0 |
NSM Bank Facility | Term Loan | Specialty Insurance Distribution (NSM) | Interest Rate Swap | Term loan - hedged |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  | 147,200,000 |  |  |  |  |  |  |
NSM Bank Facility | Term Loan | Specialty Insurance Distribution (NSM) | Interest Rate Swap | Term loan - unhedged |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  | $ 130,100,000 |  |  |  |  |  |  |
NSM Bank Facility | Term Loan | Specialty Insurance Distribution (NSM) | USD-LIBOR | Minimum |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Basis spread on variable rate | 4.25% | 4.25% |  | 5.50% | 5.50% |  |  |  |  |  |
NSM Bank Facility | Term Loan | Specialty Insurance Distribution (NSM) | USD-LIBOR | Maximum |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Basis spread on variable rate | 4.75% | 4.75% |  | 6.00% | 6.00% |  |  |  |  |  |
Debt instrument, interest rate, increase (decrease) |  |  |  | 1.25% | 1.25% |  |  |  |  |  |
NSM Bank Facility | Term Loan | Specialty Insurance Distribution (NSM) | GBP-LIBOR | Minimum |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Basis spread on variable rate |  |  |  | 6.00% | 6.00% |  |  |  |  |  |
NSM Bank Facility | Term Loan | Specialty Insurance Distribution (NSM) | GBP-LIBOR | Maximum |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Basis spread on variable rate |  |  |  | 6.50% | 6.50% |  |  |  |  |  |
Derivative, cap interest rate |  |  |  | 1.25% |  |  | 1.25% |  |  |  |
NSM Bank Facility | Revolving credit loan | Specialty Insurance Distribution (NSM) |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Total commitment under revolving credit facility | $ 15,000,000.0 |  |  |  |  | 10,000,000.0 |  |  |  |  |
Borrowings |  |  |  | $ 0 |  | $ 0 |  |  |  |  |
NSM Bank Facility | GBP Term Loan | Specialty Insurance Distribution (NSM) |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Borrowings |  |  |  | 58,200,000 | £ 42.5 |  |  |  |  |  |
Other NSM |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  | 1,300,000 |  |  |
Other NSM | Term Loan | Specialty Insurance Distribution (NSM) |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  | 1,400,000 |  |  |  |  |  |  |
Kudu Bank Facility | Kudu |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Total commitment under revolving credit facility |  |  |  | 300,000,000.0 |  |  |  |  |  |  |
Debt |  |  |  | 60,800,000 |  |  |  |  |  |  |
Kudu Bank Facility | Term Loan |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Debt |  |  |  |  |  |  |  | 86,300,000 |  |  |
Amount borrowed |  |  |  |  |  |  |  | $ 89,200,000 |  |  |
Kudu Bank Facility | Term Loan | Kudu |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Amount borrowed |  |  |  | 198,000,000.0 |  |  |  |  |  |  |
Percentage of borrowing base |  |  |  | 0.35 |  |  |  |  |  |  |
Kudu Bank Facility | Line of Credit | Kudu |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Interest Reserve |  |  |  | $ 3,900,000 |  |  |  |  |  |  |
Kudu Bank Facility | Line of Credit | Kudu | London Interbank Offered Rate (LIBOR) |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Basis spread on variable rate |  |  |  | 4.30% | 4.30% |  |  |  |  |  |
Kudu Bank Facility | Line of Credit | Kudu | Base Rate |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Basis spread on variable rate |  |  |  | 0.25% | 0.25% |  |  |  |  |  |
Kudu Bank Facility | Revolving credit loan | Kudu |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Total commitment under revolving credit facility |  |  |  | $ 102,000,000.0 |  |  |  |  |  |  |
Repayments on credit facility |  |  |  | 92,200,000 |  |  |  |  |  |  |
First Credit Facility | Other |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Total commitment under revolving credit facility |  |  |  | 16,300,000 |  |  |  |  |  |  |
First Credit Facility | Term Loan | Other |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Total commitment under revolving credit facility |  |  |  | 11,300,000 |  |  |  |  |  |  |
Repayments of lines of credit |  |  |  | 600,000 |  |  |  |  |  |  |
Amount borrowed |  |  |  | 8,800,000 |  |  |  |  |  |  |
First Credit Facility | Delayed Draw Term Loans | Other |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Total commitment under revolving credit facility |  |  |  | 3,000,000.0 |  |  |  |  |  |  |
First Credit Facility | Revolving credit loan | Other |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Total commitment under revolving credit facility |  |  |  | 2,000,000.0 |  |  |  |  |  |  |
Draw down of debt and revolving line of credit |  |  |  | 300,000 |  |  |  |  |  |  |
Second Credit Facility | Other |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Total commitment under revolving credit facility |  |  |  | 15,000,000.0 |  |  |  |  |  |  |
Second Credit Facility | Term Loan | Other |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Total commitment under revolving credit facility |  |  |  | 9,000,000.0 |  |  |  |  |  |  |
Repayments of lines of credit |  |  |  | 200,000 |  |  |  |  |  |  |
Amount borrowed |  |  |  | 8,700,000 |  |  |  |  |  |  |
Second Credit Facility | Delayed Draw Term Loans | Other |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Total commitment under revolving credit facility |  |  |  | 4,000,000.0 |  |  |  |  |  |  |
Second Credit Facility | Revolving credit loan | Other |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Total commitment under revolving credit facility |  |  |  | 2,000,000.0 |  |  |  |  |  |  |
Ark | Term Loan |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Total commitment under revolving credit facility |  |  |  | 150,000,000.0 |  |  |  |  |  |  |
Line of credit |  |  |  | 45,000,000.0 |  |  |  |  |  |  |
Ark Alesco Note | Junior Notes | Ark |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Amount borrowed |  |  | $ 30,000,000.0 |  |  |  |  |  |  |  |
Debt |  |  |  | 30,000,000.0 |  |  |  |  |  |  |
Ark Alesco Note | Junior Notes | London Interbank Offered Rate (LIBOR) | Ark |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Basis spread on variable rate |  |  | 4.60% |  |  |  |  |  |  |  |
Ark Dekania Note | Junior Notes | Ark |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Amount borrowed | € |  |  |  |  |  |  |  |  |  |  | € 12,000,000.0
Debt |  |  |  | $ 14,100,000 |  |  | € 12,000,000.0 |  |  |  |
Ark Dekania Note | Junior Notes | EURIBOR | Ark |  |  |  |  |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |  |  |  |  |
Basis spread on variable rate |  |  | 4.60% |  |  |  |  |  |  |  |

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- Definition Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6031897-161870 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(16)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 Reference 3: 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(22)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 + 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://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(22)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(16)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 + Details
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- 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/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6031897-161870 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 4: 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(22)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
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- Definition The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3255-108585 + Details
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