Earnings Per Share (Tables)

6 Months Ended

Jun. 30, 2018

Earnings Per Share [Abstract]

Summary of Earnings Per Share, Basic and Diluted

The calculation and reconciliation of basic and diluted earnings per share for the three and six month periods ended June 30 follows (in thousands, except per share data):

	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
Net income	$	176,852	$	130,987	$	351,789	$	254,680
Denominator for basic earnings per share	89,169		92,013		89,466		92,060
Dilutive securities	3,533		2,210		3,504		2,332
Denominator for diluted earnings per share	92,702		94,223		92,970		94,392
Basic earnings per share	$	1.98	$	1.42	$	3.93	$	2.77
Diluted earnings per share	$	1.91	$	1.39	$	3.78	$	2.70