Net Income per Share (Tables)

12 Months Ended

Dec. 31, 2014

Earnings Per Share [Abstract]

Computation of basic and diluted earnings per common share

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

	Year Ended December 31,
	2014		2013		2012
	(in thousands, except per share amounts)
Numerator:
Net income	$	225,464	$	176,918	$	108,460
Denominator:
Weighted-average shares outstanding, basic	72,739		72,593		72,386
Effect of dilutive stock awards	555		406		205
Adjusted weighted-average shares outstanding, diluted	73,294		72,999		72,591
Net Income per Share:
Basic earnings per common share	$	3.10	$	2.44	$	1.50
Diluted earnings per common share	$	3.08	$	2.42	$	1.49
Anti-dilutive weighted-average shares	29		1		88