Income (Loss) Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	0 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Nov. 30, 2013	Dec. 01, 2012	Nov. 30, 2013	Dec. 01, 2012
Numerator for income (loss) per share:
Net income (loss)		$ 71,548	$ 61,871	$ 194,037	$ (4,982)
Accretion of redeemable preferred stock		(26)	(26)	(77)	(77)
Cumulative preferred stock dividends		(2,814)	(2,651)	(8,318)	(7,837)
Conversion of Series G and H preferred stock	(25,603)	(25,603)		(25,603)
Income (loss) attributable to common stockholders-basic		43,105	59,194	160,039	(12,896)
Add back-interest on convertible notes			1,334
Income (loss) attributable to common stockholders-diluted		$ 43,105	$ 60,528	$ 160,039	$ (12,896)
Denominator:
Basic weighted average shares		938,994	891,031	911,608	889,187
Outstanding options and restricted shares, net (in shares)		48,843	1,977	41,227
Convertible notes (in shares)			24,800
Diluted weighted average shares		987,837	917,808	952,835	889,187
Basic income (loss) per share (in dollars per share)		$ 0.05	$ 0.07	$ 0.18	$ (0.01)
Diluted income (loss) per share (in dollars per share)		$ 0.04	$ 0.07	$ 0.17	$ (0.01)
Antidilutive securities excluded from computation of earnings per share
Potential common shares excluded from the computation of diluted income (loss) per share		48,364	103,487	57,233	140,588
Stock options
Antidilutive securities excluded from computation of earnings per share
Potential common shares excluded from the computation of diluted income (loss) per share		23,564	70,868	32,433	83,169
Convertible notes
Antidilutive securities excluded from computation of earnings per share
Potential common shares excluded from the computation of diluted income (loss) per share		24,800		24,800	24,800
Convertible preferred stock
Antidilutive securities excluded from computation of earnings per share
Potential common shares excluded from the computation of diluted income (loss) per share			32,619		32,619
Restricted shares and restricted stock units
Antidilutive securities excluded from computation of earnings per share
Potential common shares excluded from the computation of diluted income (loss) per share				0	12,753