Quarterly Financial Data (unaudited) (Tables)

12 Months Ended

Dec. 31, 2016

Quarterly financial data (unaudited)

Schedule of unaudited quarterly results of operations

	Quarter Ended
	Mar 31,		Jun 30,		Sep 30,		Dec 31,		Mar 31,		Jun 30,		Sep 30,		Dec 31,
	2015		2015		2015		2015		2016		2016		2016		2016
	(in thousands, except share data)
Revenues	$	278,315	$	304,702	$	313,126	$	326,697	$	343,328	$	350,139	$	355,101	$	370,487
Income before taxes		30,205		118,049		119,996		124,703		143,991		142,271		144,573		149,403
Net income		19,332		76,118		77,042		80,899		92,858		91,803		93,276		96,988
Net income per share:
Basic	$	0.19	$	0.74	$	0.75	$	0.79	$	0.90	$	0.89	$	0.91	$	0.94
Diluted	$	0.19	$	0.70	$	0.71	$	0.74	$	0.85	$	0.84	$	0.86	$	0.89