Consolidated Statements Of Income And Comprehensive Income - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2019		Sep. 30, 2018		Sep. 30, 2019		Sep. 30, 2018
OPERATING REVENUES
Earned premiums	$ 1,300,032		$ 1,185,323		$ 3,703,470		$ 3,484,528
Net investment income	113,382		106,307		339,395		319,710
Net realized investment gains (losses)	150		(496)		764		(9,084)
Change in fair value of equity securities	31,994		426,571		1,069,224		417,410
Net investment gains	32,144		426,075		1,069,988		408,326
Products revenues	386,708		362,577		1,237,178		1,129,036
Services and other revenues	200,792		155,667		594,631		456,833
Total Operating Revenues	2,033,058		2,235,949		6,944,662		5,798,433
OPERATING EXPENSES
Losses and loss adjustment expenses	752,134		736,846		2,118,000		1,951,142
Underwriting, acquisition and insurance expenses	475,219		441,961		1,392,747		1,317,921
Products expenses	354,404		341,718		1,098,968		1,062,000
Services and other expenses	153,358		132,024		498,760		394,311
Amortization of intangible assets	35,695	[1]	27,795	[2]	112,663	[3]	86,259	[4]
Impairment of goodwill and intangible assets	0		0		0		14,904
Total Operating Expenses	1,770,810		1,680,344		5,221,138		4,826,537
Operating Income	262,248		555,605		1,723,524		971,896
Interest expense	47,465		37,961		129,022		114,722
Net foreign exchange gains	(53,850)		(1,383)		(57,001)		(65,427)
Loss on early extinguishment of debt	6,705		0		6,705		0
Income Before Income Taxes	261,928		519,027		1,644,798		922,601
Income tax expense	57,975		109,999		356,849		299,580
Net Income	203,953		409,028		1,287,949		623,021
Net income (loss) attributable to noncontrolling interests	(1,684)		(410)		8,587		(342)
Net Income to Shareholders	205,637		409,438		1,279,362		623,363
OTHER COMPREHENSIVE INCOME
Net holding gains (losses) arising during the period	48,315		(91,002)		329,113		(306,069)
Reclassification adjustments for net losses included in net income	203		10,573		760		5,496
Change in net unrealized gains (losses) on available-for-sale investments, net of taxes	48,518		(80,429)		329,873		(300,573)
Change in foreign currency translation adjustments, net of taxes	(4,606)		(14,471)		(5,978)		(19,968)
Change in net actuarial pension loss, net of taxes	462		509		2,338		1,741
Total Other Comprehensive Income (Loss)	44,374		(94,391)		326,233		(318,800)
Comprehensive Income (Loss)	248,327		314,637		1,614,182		304,221
Comprehensive income (loss) attributable to noncontrolling interests	(1,742)		(469)		8,538		(382)
Comprehensive Income to Shareholders	$ 250,069		$ 315,106		$ 1,605,644		$ 304,603
NET INCOME PER SHARE
Basic (in dollars per share)	$ 13.97		$ 28.56		$ 92.92		$ 44.29
Diluted (in dollars per share)	$ 13.95		$ 28.50		$ 92.84		$ 44.21

[1] Segment profit for the Markel Ventures segment includes amortization of intangible assets attributable to Markel Ventures. Amortization of intangible assets is not allocated to any other reportable segments.

[2] Segment profit for the Markel Ventures segment includes amortization of intangible assets attributable to Markel Ventures. Amortization of intangible assets is not allocated to any other reportable segments.

[3] Segment profit for the Markel Ventures segment includes amortization of intangible assets attributable to Markel Ventures. Amortization of intangible assets is not allocated to any other reportable segments.

[4] Segment profit for the Markel Ventures segment includes amortization of intangible assets attributable to Markel Ventures. Amortization of intangible assets is not allocated to any other reportable segments.