Stock Repurchase (Details) - shares	3 Months Ended	6 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Mar. 31, 2017
Equity [Abstract]
Stock repurchase program, number of shares authorized to be repurchased	15,000,000.0	15,000,000.0
Repurchase of common stock (in shares)	0	0
Treasury stock, number of shares held	19,303,793	19,303,793	20,370,075