Condensed Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Comprehensive income (loss) (pretax):
Pretax earnings (loss)	$ 195,051	$ 179,048
Comprehensive income (loss) (tax effect):
Net earnings	(70,577)	(66,080)
Comprehensive income (loss) (net of tax):
Net earnings	124,474	112,968
Other comprehensive income (loss):
Foreign currency translation (pretax)	2,743	(3,762)
Foreign currency translation (tax effect)	0	0
Foreign currency translation (net of tax)	2,743	(3,762)
Unrealized gain (loss) on investments (pretax)	26,612	89
Unrealized gain (loss) on investments (tax effect)	(9,314)	(68)
Unrealized gain (loss) on investments (net of tax)	17,298	21
Change in fair value of cash flow hedges (pretax)	1,345	10,196
Change in fair value of cash flow hedges (tax effect)	(511)	(3,874)
Change in fair value of cash flow hedges (net of tax)	834	6,322
Total comprehensive income (loss) (pretax)	225,751	185,571
Total comprehensive income (loss) (tax effect)	(80,402)	(70,022)
Total comprehensive income (loss) (net of tax)	$ 145,349	$ 115,549