Earnings Per Share

Class A and Class B basic earnings per share and Class B diluted earnings per share are calculated under the two-class method. The two-class method allocates earnings to each class of stock based upon its dividend rights. Class B shares are convertible into Class A shares at a conversion ratio of 2,400 to 1. See Note 12, "Capital Stock".

Class A diluted earnings per share are calculated under the if-converted method, which reflects the conversion of Class B shares to Class A shares. Diluted earnings per share calculations include the dilutive effect of assumed issuance of stock-based awards under compensation plans that have the option to be paid in stock using the treasury stock method. See Note 10, "Incentive and Deferred Compensation Plans".

At December 31, 2017, we recorded a one-time net non-cash tax expense of $10.1 million as a result of the enactment of the Tax Cuts and Jobs Act ("TCJA") on December 22, 2017. See Note 11, "Income Taxes". This resulted in a reduction in Class A basic earnings per share of $0.22 and diluted earnings per share of $0.19, and a reduction in Class B basic earnings per share of $33 and diluted earnings per share of $32.

A reconciliation of the numerators and denominators used in the basic and diluted per-share computations is presented as follows for each class of common stock:



(dollars in thousands, except per share data)						For the years ended December 31,
	2018					2017					2016
	Allocated net income (numerator)		Weighted shares (denominator)	Per- share amount		Allocated net income (numerator)		Weighted shares (denominator)	Per- share amount		Allocated net income (numerator)		Weighted shares (denominator)	Per- share amount
Class A – Basic EPS:
Income available to Class A stockholders	$	285,864	46,188,637	$	6.19	$	195,386	46,186,831	$	4.23	$	208,644	46,188,952	$	4.52
Dilutive effect of stock-based awards	0		25,776	—		0		49,832	—		0		145,551	—
Assumed conversion of Class B shares	2,360		6,100,800	—		1,613		6,100,800	—		1,722		6,100,800	—
Class A – Diluted EPS:
Income available to Class A stockholders on Class A equivalent shares	$	288,224	52,315,213	$	5.51	$	196,999	52,337,463	$	3.76	$	210,366	52,435,303	$	4.01
Class B – Basic EPS:
Income available to Class B stockholders	$	2,360	2,542	$	928	$	1,613	2,542	$	635	$	1,722	2,542	$	678
Class B – Diluted EPS:
Income available to Class B stockholders	$	2,359	2,542	$	928	$	1,613	2,542	$	634	$	1,721	2,542	$	677