Fair Value of Financial Instruments (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Jun. 30, 2014
Investments in time and call deposits
Unrealized gains (losses) on available-for-sale securities	$ 0
Minimum
Investments in time and call deposits
Maturity of time deposits	1 month
Period of ability to redeem invested amounts on call deposits	31 days
Maximum
Investments in time and call deposits
Maturity of time deposits	6 months
Period of ability to redeem invested amounts on call deposits	95 days