Consolidated Statements Of Income (Loss) And Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020		Mar. 31, 2019
OPERATING REVENUES
Earned premiums	$ 1,330,709		$ 1,203,977
Net investment income	88,243		114,182
Net realized investment gains	9,738		681
Change in fair value of equity securities	(1,691,179)		611,510
Net investment gains (losses)	(1,681,441)		612,191
Products revenues	352,161		348,794
Services and other revenues	245,994		193,344
Total Operating Revenues	335,666		2,472,488
OPERATING EXPENSES
Losses and loss adjustment expenses	1,076,348		687,746
Underwriting, acquisition and insurance expenses	495,163		455,212
Products expenses	314,071		319,426
Services and other expenses	217,556		174,606
Amortization of intangible assets	37,858	[1]	40,668	[2]
Total Operating Expenses	2,140,996		1,677,658
Operating Income (Loss)	(1,805,330)		794,830
Interest expense	(45,030)		(40,290)
Net foreign exchange gains (losses)	78,301		(21,864)
Income (Loss) Before Income Taxes	(1,772,059)		732,676
Income tax (expense) benefit	370,683		(155,163)
Net Income (Loss)	(1,401,376)		577,513
Net income attributable to noncontrolling interests	(4,387)		(1,086)
Net Income (Loss) to Shareholders	(1,405,763)		576,427
OTHER COMPREHENSIVE INCOME
Net holding gains arising during the period	64,377		152,331
Reclassification adjustments for net gains (losses) included in net income (loss)	1,187		(246)
Change in net unrealized gains on available-for-sale investments, net of taxes	65,564		152,085
Change in foreign currency translation adjustments, net of taxes	(12,734)		2,377
Change in net actuarial pension loss, net of taxes	0		1,361
Total Other Comprehensive Income	52,830		155,823
Comprehensive Income (Loss)	(1,348,546)		733,336
Comprehensive income attributable to noncontrolling interests	(4,263)		(1,091)
Comprehensive Income (Loss) to Shareholders	$ (1,352,809)		$ 732,245
NET INCOME (LOSS) PER SHARE
Basic (in dollars per share)	$ (100.60)		$ 42.81
Diluted (in dollars per share)	$ (100.60)		$ 42.76

[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 the Company's Insurance and Reinsurance 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 the Company's Insurance and Reinsurance segments.