Net Income per Share (Additional Information) (Details) - shares	3 Months Ended		6 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Reconciliations of basic to diluted weighted-average common shares outstanding
Weighted-average shares used in basic computation	32,511,000	34,632,000	32,812,000	34,629,000
Dilutive effect of stock-based awards	264,000	322,000	0	312,000
Weighted-average shares used in diluted computation	32,775,000	34,954,000	32,812,000	34,941,000
Excluded NSUs
Options excluded in the computation of diluted income per share
Options excluded in the computation of diluted income per share (in shares)	177,000	143,000	480,000	143,000
Excluded restricted stock units (RSUs)
Options excluded in the computation of diluted income per share
Options excluded in the computation of diluted income per share (in shares)	457,000	888,000	457,000	888,000
Excluded outside director restricted stock awards (RSAs)
Options excluded in the computation of diluted income per share
Options excluded in the computation of diluted income per share (in shares)	0	0	9,000	0
Excluded stock appreciation rights (SARs)
Options excluded in the computation of diluted income per share
Options excluded in the computation of diluted income per share (in shares)	510,000	525,000	700,000	525,000