INVESTMENTS - Summary of Marketable Securities which are Classified as Available-for-Sale (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	May 31, 2014	Nov. 30, 2013
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 194,172	$ 330,143
Gross Unrealized Gains	489	188
Gross Unrealized Losses	0	0
Aggregate Fair Value	194,661	330,331
Money market funds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	18,810	245,953
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Aggregate Fair Value	18,810	245,953
Corporate bonds and commercial paper
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	158,585	77,442
Gross Unrealized Gains	341	66
Gross Unrealized Losses	0	0
Aggregate Fair Value	158,926	77,508
U.S. Government debt and agency securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	16,575	6,012
Gross Unrealized Gains	2	1
Gross Unrealized Losses	0	0
Aggregate Fair Value	16,577	6,013
Term deposits
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		536
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Aggregate Fair Value		536
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	202	200
Gross Unrealized Gains	146	121
Gross Unrealized Losses	0	0
Aggregate Fair Value	$ 348	$ 321