Earnings Per Share (Tables)

6 Months Ended

Sep. 30, 2011

Earnings Per Share [Abstract]

Weighted-average shares outstanding for basic and diluted net income per share

	Three Months Ended September 30,				Six Months Ended September 30,
	2011		2010		2011		2010
Net income	$	20,496	$	13,430	$	39,479	$	25,522
Basic net income per share:
Weighted-average shares outstanding — Basic		58,664		57,870		58,511		57,830
Basic net income per common share	$	0.35	$	0.23	$	0.67	$	0.44
Net income	$	20,496	$	13,430	$	39,479	$	25,522
Diluted net income per share:
Weighted-average shares outstanding — Basic		58,664		57,870		58,511		57,830
Effect of potentially dilutive securities		341		286		391		302
Weighted-average shares outstanding — Diluted		59,005		58,156		58,902		58,132
Diluted net income per common share	$	0.35	$	0.23	$	0.67	$	0.44