Quarterly Financial Data (Tables)

12 Months Ended

Dec. 31, 2016

Quarterly Financial Data [Abstract]

Summary Of Quarterly Financial Data

	2016
	March 31		June 30		September 30		December 31
Revenue	$	834,459	$	998,383	$	1,036,982	$	1,034,560
Operating income (loss)	$	(46,604)	$	40,895	$	9,726	$	30,550
Net income (loss)	$	(26,432)	$	25,596	$	7,799	$	15,975
Basic earnings (loss) per share	$	(0.88)	$	0.88	$	0.27	$	0.55
Diluted earnings (loss) per share	$	(0.88)	$	0.87	$	0.27	$	0.55
	2015
	March 31		June 30		September 30		December 31
Revenue	$	1,089,043	$	1,197,783	$	1,216,890	$	997,507
Operating income	$	197,801	$	227,416	$	234,759	$	103,613
Net income	$	122,641	$	140,204	$	144,883	$	67,874
Basic earnings per share	$	3.95	$	4.51	$	4.65	$	2.19
Diluted earnings per share	$	3.88	$	4.45	$	4.59	$	2.17