Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2017	Mar. 31, 2017
Condensed Consolidated Balance Sheets
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	450,000,000	450,000,000
Common stock, shares issued	58,620,727	58,342,201
Common stock, shares outstanding	55,115,380	54,974,526
Treasury stock, shares at cost	3,505,347	3,367,675