Note 15 - Quarterly Financial Information (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Quarterly Financial Information [Table Text Block]

	Quarter
	First		Second		Third		Fourth
2019:
Operating revenues	$	2,089,627	$	2,261,647	$	2,363,660	$	2,450,323
Operating income	$	167,795	$	193,093	$	167,862	$	205,074
Net earnings	$	119,601	$	133,633	$	118,410	$	144,676
Basic earnings per share	$	1.10	$	1.24	$	1.11	$	1.36
Diluted earnings per share	$	1.09	$	1.23	$	1.10	$	1.35
2018:
Operating revenues	$	1,948,245	$	2,139,027	$	2,209,760	$	2,317,842
Operating income	$	168,781	$	214,812	$	174,688	$	122,740
Net earnings	$	118,142	$	151,652	$	131,110	$	88,681
Basic earnings per share	$	1.08	$	1.39	$	1.20	$	0.81
Diluted earnings per share	$	1.07	$	1.37	$	1.19	$	0.81