Net Income Per Share (Tables)

3 Months Ended

Mar. 31, 2017

Earnings Per Share [Abstract]

Basic and Diluted Net Income (Loss) Per Share

The calculations of basic and diluted net income per share are as follows:

	Three Months Ended March 31,
	2017		2016
Net income - basic	$	248,931	$	181,385
Effect of dilutive securities:
Convertible senior notes - interest expense related to contractual coupon interest rate and amortization of discount and note issuance costs	—		56
Net income - diluted	$	248,931	$	181,441
(Shares in thousands)
Weighted average shares - basic	105,572		104,290
Effect of dilutive securities:
Stock options	9,050		8,147
Restricted stock	484		469
Convertible senior notes	—		44
Warrants	—		1,278
Dilutive potential shares	9,534		9,938
Weighted average shares - diluted	115,106		114,228
Net income per share - basic	$	2.36	$	1.74
Net income per share - diluted	$	2.16	$	1.59

Antidilutive Securities

Shares which have been excluded from diluted per share amounts because their effect would have been antidilutive, include the following:

	Three Months Ended March 31,
(Shares in thousands)	2017	2016
Stock options	11,535	7,539
Restricted stock	18	19