Common Stock (Other) (Details)	12 Months Ended
	Mar. 31, 2018 item shares	Mar. 31, 2017 shares	Jul. 01, 2013 $ / shares shares
Common stock
Authorized capital stock (in shares)			500,000,000
Par value of capital stock (in dollars per share) | $ / shares			$ 0.01
Common stock, shares authorized	450,000,000	450,000,000	450,000,000
Preferred stock, shares authorized	50,000,000	50,000,000	50,000,000
Number of votes entitled to shareholders | item	1