Quarterly Results of Operations (unaudited)

12 Months Ended

Dec. 31, 2015

Quarterly Financial Information Disclosure [Abstract]

Quarterly Results of Operations (unaudited)

Note 17.  Quarterly Results of Operations (unaudited)

	Year ended December 31, 2015
(in thousands, except per share data)	First quarter		Second quarter		Third quarter		Fourth quarter		Year
Operating revenue	$	350,831	$	401,660	$	396,637	$	356,380	$	1,505,508
Operating expenses	298,401		331,677		328,348		314,541		1,272,967
Investment income	6,539		15,705		7,220		4,244		33,708
Income before income taxes	58,969		85,688		75,509		46,083		266,249
Net income	$	38,833	$	56,150	$	49,562	$	30,133	$	174,678
Earnings per share (1)
Net income per share
Class A common stock – basic	$	0.83	$	1.21	$	1.06	$	0.65	$	3.75
Class A common stock – diluted	$	0.74	$	1.07	$	0.94	$	0.57	$	3.33
Class B common stock – basic	$	125	$	181	$	160	$	97	$	563
Class B common stock – diluted	$	125	$	180	$	159	$	97	$	562

(1) The cumulative sum of quarterly basic and diluted net income per share amounts may not equal total basic and diluted net income per share for the year due to differences in weighted average shares and equivalent shares outstanding for each of the periods presented.

	Year ended December 31, 2014
(in thousands, except per share data)	First quarter		Second   quarter		Third  quarter		Fourth  quarter		Year
Operating revenue	$	326,247	$	373,978	$	369,638	$	337,256	$	1,407,119
Operating expenses	267,819		306,060		308,550		301,843		1,184,272
Investment income	11,599		6,872		7,604		2,342		28,417
Income before income taxes	70,027		74,790		68,692		37,755		$	251,264
Net income	$	46,262	$	49,047	$	46,900	$	25,296	$	167,505
Earnings per share (1)
Net income per share
Class A common stock – basic	$	0.99	$	1.05	$	1.01	$	0.54	$	3.59
Class A common stock –diluted	$	0.88	$	0.94	$	0.90	$	0.48	$	3.18
Class B common stock – basic	$	149	$	158	$	151	$	81	$	539
Class B common stock – diluted	$	149	$	158	$	151	$	81	$	538

(1) The cumulative sum of quarterly basic and diluted net income per share amounts may not equal total basic and diluted net income per share for the year due to differences in weighted average shares and equivalent shares outstanding for each of the periods presented.