Earnings per Share (Tables)

6 Months Ended

Jun. 30, 2013

Earnings Per Share [Abstract]

Schedule of calculation of basic and diluted earnings per share

The following table sets forth the calculations of basic and diluted earnings per share:

	For the Three Months Ended June 30,				For the Six Months Ended June 30,
	2013		2012		2013		2012
	(in thousands, except per share amounts)
Net income	$	76,522	$	24,889	$	93,249	$	51,225
Basic weighted-average common shares outstanding	66,295		64,585		66,254		64,345
Add: dilutive effect of stock options, unvested RSUs, and contingent PSUs	1,598		2,149		1,457		2,182
Add: dilutive effect of 3.50% Senior Convertible Notes	—		822		—		1,279
Diluted weighted-average common shares outstanding	67,893		67,556		67,711		67,806
Basic net income per common share	$	1.15	$	0.39	$	1.41	$	0.80
Diluted net income per common share	$	1.13	$	0.37	$	1.38	$	0.76