SELECTED QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Tables)

12 Months Ended

Dec. 31, 2018

Schedule of Selected Quarterly Financial Information

Selected quarterly financial information for each of the quarters in the years ended December 31, 2018 and 2017 is as follows (in thousands, except per share data):

	March 31, 2018		June 30, 2018		September30, 2018		December 31, 2018
Revenue	$	440,916	$	449,929	$	462,728	$	482,193
Operating income		58,705		61,712		64,419		64,649
Net income		37,777		39,197		40,994		41,239
Basic earnings per share:
Net income	$	0.32	$	0.33	$	0.35	$	0.35
Diluted earnings per share:
Net income	$	0.32	$	0.33	$	0.34	$	0.35

	March 31, 2017		June 30, 2017		September 30, 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