XML 63 R42.htm IDEA: XBRL DOCUMENT v3.24.0.1

Reinsurance (Tables)

12 Months Ended

Dec. 31, 2023

Reinsurance Disclosures [Abstract]

Effect Of Reinsurance And Retrocessional Reinsurance On Consolidated Premiums Written And Earned

The following tables summarize the effect of reinsurance and retrocessional reinsurance on premiums written and earned.

			Year Ended December 31, 2023
(dollars in thousands)			Direct						Assumed						Ceded						Net Premiums
Underwriting:
Written			$	8,657,266					$	1,620,366					$	(1,878,844)					$	8,398,788
Earned			$	8,363,710					$	1,616,630					$	(1,683,648)					$	8,296,692
Program services and other fronting:
Written			2,649,217						1,075,388						(3,725,818)						(1,213)
Earned			2,636,179						937,400						(3,574,792)						(1,213)
Consolidated:
Written			$	11,306,483					$	2,695,754					$	(5,604,662)					$	8,397,575
Earned			$	10,999,889					$	2,554,030					$	(5,258,440)					$	8,295,479

			Year Ended December 31, 2022
(dollars in thousands)			Direct						Assumed						Ceded						Net Premiums
Underwriting:
Written			$	8,085,812					$	1,761,726					$	(1,640,165)					$	8,207,373
Earned			$	7,379,766					$	1,589,920					$	(1,378,191)					$	7,591,495
Program services and other fronting:
Written			2,644,138						710,006						(3,358,127)						(3,983)
Earned			2,688,804						656,885						(3,349,392)						(3,703)
Consolidated:
Written			$	10,729,950					$	2,471,732					$	(4,998,292)					$	8,203,390
Earned			$	10,068,570					$	2,246,805					$	(4,727,583)					$	7,587,792

			Year Ended December 31, 2021
(dollars in thousands)			Direct						Assumed						Ceded						Net Premiums
Underwriting:
Written			$	6,863,229					$	1,622,700					$	(1,360,763)					$	7,125,166
Earned			$	6,275,078					$	1,482,755					$	(1,250,392)					$	6,507,441
Program services and other fronting:
Written			2,644,955						307,798						(2,958,188)						(5,435)
Earned			2,453,990						261,591						(2,719,993)						(4,412)
Consolidated:
Written			$	9,508,184					$	1,930,498					$	(4,318,951)					$	7,119,731
Earned			$	8,729,068					$	1,744,346					$	(3,970,385)					$	6,503,029

Effect of Reinsurance And Retrocessional Reinsurance on Incurred Losses and Loss Adjustment Expenses

The following table summarizes the effect of reinsurance and retrocessional reinsurance on losses and loss adjustment expenses in the Company's underwriting operations.

			Years ended December 31,
(dollars in thousands)			2023						2022						2021
Gross losses and loss adjustment expenses			$	6,817,630					$	5,281,424					$	4,477,752
Ceded losses and loss adjustment expenses			(1,496,265)						(834,648)						(893,230)
Net losses and loss adjustment expenses			$	5,321,365					$	4,446,776					$	3,584,522

X

- Definition

Effects of Reinsurance on Losses [Table Text Block]

+ References

No definition available.

+ Details

Name:	mkl_EffectsofReinsuranceonLossesTableTextBlock
Namespace Prefix:	mkl_
Data Type:	dtr-types1:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of the effects of reinsurance, for example, but not limited to, disclosure of direct, assumed, and ceded insurance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-SubTopic 605
-Topic 944
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479655/944-605-50-1

+ Details

Name:	us-gaap_EffectsOfReinsuranceTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- References

No definition available.

+ Details

Name:	us-gaap_ReinsuranceDisclosuresAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration