Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Numerator
Net income	$ 16,732	$ 20,692
Denominator
Denominator for basic earnings per share — weighted average shares outstanding (in shares)	51,956	51,222
Dilutive effect of unvested restricted common stock (including restricted stock units) and options issued to employees and directors (in shares)	577	818
Denominator for diluted earnings per share (in shares)	52,533	52,040
Earnings per Common Share:
Basic net earnings per share (in USD per share)	$ 0.32	$ 0.40
Diluted net earnings per share (in USD per share)	$ 0.32	$ 0.40