Consolidated Statements of Earnings and Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenues
Net premiums earned	$ 1,605,458	$ 1,604,763
Net investment income	113,476	153,484
Change in the fair value of equity securities	(138,777)	112,728
Net realized capital gains	(10,003)	12,931
Change in allowance for credit losses on available for sale securities	(582)	1,972
Product and service revenues	1,149,162	767,835
Total revenues	2,718,734	2,653,713
Costs and Expenses
Net loss and loss adjustment expenses	941,787	1,112,070
Commissions, brokerage and other underwriting expenses	477,165	476,036
Other operating expenses	1,028,892	723,889
Corporate administration	10,723	9,558
Amortization of intangible assets	14,082	11,478
Interest expense	32,110	23,752
Total costs and expenses	2,504,759	2,356,783
Earnings before income taxes	213,975	296,930
Income taxes	45,082	58,867
Net earnings	168,893	238,063
Net earnings attributable to noncontrolling interest	43,212	8,022
Net earnings attributable to Alleghany stockholders	125,681	230,041
Net earnings	168,893	238,063
Other comprehensive income (loss):
Change in unrealized gains, net of deferred taxes of ($163,282) and ($57,932) in 2022 and 2021, respectively	(614,251)	(217,935)
Change in unrealized currency translation adjustment, net of deferred taxes of ($139) and $654 for 2022 and 2021, respectively	(523)	2,461
Retirement plans	130	(965)
Comprehensive (loss) income	(437,389)	9,851
Comprehensive income attributable to noncontrolling interests	43,212	8,022
Comprehensive (loss) income attributable to Alleghany stockholders	$ (480,601)	$ 1,829
Basic earnings per share attributable to Alleghany stockholders	$ 9.29	$ 16.44
Diluted earnings per share attributable to Alleghany stockholders	$ 9.29	$ 16.37
Accumulated Net Unrealized Investment Gain Loss
Other comprehensive income (loss):
Less: reclassification for net realized capital gains and change in allowance for credit losses on available for sale securities, net of taxes of $2,223 and ($3,130) for 2022 and 2021, respectively	$ 8,362	$ (11,773)