SELECTED QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Tables)

12 Months Ended

Dec. 31, 2017

Schedule of Selected Quarterly Financial Information

Selected quarterly financial information for each of the quarters in the years ended December 31, 2017 and 2016 is as follows (in thousands, except per share data):

	March 31, 2017		June 30, 2017		September30, 2017		December 31, 2017
Revenue	$	445,684	$	436,393	$	442,845	$	440,576
Operating income		69,039		65,279		60,815		65,263
Net income		50,047		45,475		41,178	$	41,340
Basic earnings per share:
Net income	$	0.42	$	0.38	$	0.35	$	0.35
Diluted earnings per share:
Net income	$	0.42	$	0.38	$	0.35	$	0.35

	March 31, 2016		June 30, 2016		September 30, 2016		December 31, 2016
Revenue	$	447,385	$	463,331	$	474,935	$	464,134
Operating income		64,928		77,176		73,953		80,359
Net income		46,307		57,583		55,340		60,689
Basic earnings per share:
Net income	$	0.39	$	0.49	$	0.47	$	0.52
Diluted earnings per share:
Net income	$	0.39	$	0.49	$	0.47	$	0.52