Earnings Per Share (Tables)

9 Months Ended

Sep. 30, 2018

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2018		2017		2018		2017
	(In thousands, except per share amounts)
Amounts attributable to common stockholders:
Net income:
Net income — basic	$	68,935	$	56,164	$	254,162	$	299,347
After tax interest on convertible debt	15		13		45		38
Net income — diluted	$	68,950	$	56,177	$	254,207	$	299,385
Weighted average shares (denominator):
Weighted average shares — basic	180,858		187,435		182,859		187,761
Stock options	4,284		4,575		4,364		4,448
Restricted stock units	197		112		173		87
Convertible debt	121		121		121		121
Weighted average shares — diluted	185,460		192,243		187,517		192,417
Net income per share:
Basic	$	0.38	$	0.30	$	1.39	$	1.59
Diluted	$	0.37	$	0.29	$	1.36	$	1.56

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

	Three Months Ended		Nine Months Ended
	September 30,		September 30,
	2018	2017	2018	2017
	(In thousands)		(In thousands)
Anti-dilutive options	831	—	980	878