Notes Payable and Long-Term Debt - Japan Line of Credit (Details) - Japan Credit Facility $ in Millions	12 Months Ended
	Mar. 31, 2016 USD ($)	Mar. 31, 2016 JPY (¥)
Notes Payable and Long-Term Debt
Debt Instrument, Covenant Compliance, Period of Not Having Losses	2 years
Debt Instrument, Covenant Compliance, Interest Coverage Ratio	1
Maximum
Notes Payable and Long-Term Debt
Current borrowing capacity	$ 49	¥ 5,500,000,000
Debt Instrument, Term	6 months
Tokyo Interbank Offered Rate (TIBOR)
Notes Payable and Long-Term Debt
Spread on variable interest rate (as a percent)	0.40%
Debt Instrument, Tokyo Interbank Offered Rate (TIBOR)	0.10%	0.10%
Debt Instrument, Interest Rate, Effective Percentage	0.50%	0.50%