Quarterly Results of Operations (unaudited) (Tables)

12 Months Ended

Dec. 31, 2020

Quarterly Financial Information Disclosure [Abstract]

Selected Quarterly Financial Data

Selected quarterly financial data for 2020 and 2019 are presented below:

	Quarter Ended
	March 31			June 30		September 30		December 31
	($ in millions, except per share data)
2020
Revenues	$	1,482.9		$	2,227.4	$	2,522.9	$	2,663.5
Net earnings (losses)(1)		(361.2	)		177.4		126.5		159.1
Basic earnings (losses) per share of common stock(1)(2)		(25.19	)		12.39		8.86		11.28
2019
Revenues	$	2,321.2		$	2,258.7	$	2,159.9	$	2,300.8
Net earnings (losses)(1)		440.2			295.5		90.4		31.7
Basic earnings (losses) per share of common stock(1)(2)		30.40			20.46		6.27		2.20

(1) Attributable to Alleghany stockholders.

(2) Earnings per share by quarter may not equal the amount for the full year due to the timing of repurchases of Common Stock, as well as rounding.