Net Income Per Share (Tables)

3 Months Ended

Mar. 31, 2014

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,
	2014		2013
Net income - basic and diluted	$	65,443	$	98,874
(Shares in thousands)
Weighted average shares - basic	98,709		96,878
Effect of dilutive securities:
Stock options	9,879		10,276
Restricted stock	401		325
Warrants	3,162		1,890
Dilutive potential shares	13,442		12,491
Weighted average shares - diluted	112,151		109,369
Net income per share - basic	$	0.66	$	1.02
Net income per share - diluted	$	0.58	$	0.90

Antidilutive Securities

Shares which have been excluded from the March 31, 2014 and 2013 diluted per share amounts because their effect would have been antidilutive, include the following:

	Three months ended March 31,
(Shares in thousands)	2014	2013
Stock options	3,646	3,868
Convertible senior notes	4,761	4,761