Convertible Notes (Narrative) (Detail) (USD $)	3 Months Ended		12 Months Ended				1 Months Ended	3 Months Ended		9 Months Ended	12 Months Ended				0 Months Ended	3 Months Ended		12 Months Ended		3 Months Ended	12 Months Ended	1 Months Ended	3 Months Ended	12 Months Ended	0 Months Ended	1 Months Ended					12 Months Ended			12 Months Ended				12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	May 16, 2011	Jan. 31, 2012 Series 2012 Notes [Member]	Dec. 31, 2013 Series 2012 Notes [Member]	Sep. 30, 2013 Series 2012 Notes [Member]	Sep. 30, 2013 Series 2012 Notes [Member]	Dec. 31, 2013 Series 2012 Notes [Member]	Dec. 31, 2012 Series 2012 Notes [Member]	Aug. 01, 2013 Series 2012 Notes [Member]	Feb. 29, 2012 Series 2012 Notes [Member]	May 16, 2011 May 2015 Notes [Member]	Dec. 31, 2013 May 2015 Notes [Member]	Sep. 30, 2013 May 2015 Notes [Member]	Dec. 31, 2013 May 2015 Notes [Member]	Dec. 31, 2012 May 2015 Notes [Member]	Sep. 30, 2013 Purchased Call Options [Member]	Dec. 31, 2013 Purchased Call Options [Member]	Jan. 31, 2013 Warrants [Member]	Sep. 30, 2013 Warrants [Member]	Dec. 31, 2013 Warrants [Member]	Nov. 01, 2010 February 2015 Notes [Member]	Jan. 31, 2012 February 2015 Notes [Member]	Dec. 31, 2013 February 2015 Notes [Member]	Sep. 30, 2013 February 2015 Notes [Member]	Aug. 01, 2013 February 2015 Notes [Member]	Feb. 29, 2012 February 2015 Notes [Member]	Dec. 31, 2013 Non-recourse Notes [Member]	Dec. 31, 2012 Non-recourse Notes [Member]	Nov. 02, 2009 Non-recourse Notes [Member]	Dec. 31, 2013 Term Loan. [Member]	Dec. 31, 2012 Term Loan. [Member]	Oct. 28, 2013 Term Loan. [Member]	Oct. 28, 2013 Term Loan. [Member] Base Rate [Member]	Dec. 31, 2013 Purchased Call Options [Member]	Dec. 31, 2012 Purchased Call Options [Member]
Debt Instrument [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount																																						24,800,000	23,000,000
Convertible notes														$ 10,000,000	$ 155,300,000										$ 92,000,000	$ 169,000,000			$ 1,000,000	$ 10,000,000			$ 300,000,000
Incentive fee per each $1,000 principal amount tendered to convert debt																										5.00
Principal amount a $5 incentive cash payment per each to convert debt	1,000							1,000			1,000															1,000
Induced conversion of convertible debt expense							845,000																			800,000
Deferred issue costs, incentive payment allocated							765,000
Adjustments to additional paid in capital, equity component of convertible debt				10,692,000	11,870,000		52,000			10,900,000								12,300,000
Noted obligation allocated to deferred tax assets							28,000			5,900,000								6,600,000
Debt instrument, interest rate (in Percent)							2.875%									3.75%	3.75%	3.75%								2.875%							10.25%			2.24%	1.00%
Convertible note rate conversion trading days (in days)	0	0	0
Convertible Notes rate conversion consecutive trading days (in days)	30	30	30
Convertible notes due upon demand within (in years)			1
Total debt discount																18,900,000		18,900,000										16,800,000
Unamortized discount of liability component							(2,300,000)	(7,370,000)			(7,370,000)	(13,472,000)				(6,997,000)		(6,997,000)	(11,817,000)
Minimum conversion price percent for note conversion (in Percent)								130.00%								130.00%
Convertible Notes rate conversion business day period (in days)	5		5
Convertible Notes rate conversion consecutive trading day period (in days)	0		5
Maximum percent of common stock closing price and conversion rate to convert note (in Percent)											98.00%					98.00%
Debt Instrument, Interest Rate, Effective Percentage						7.50%	7.30%		7.30%	7.30%					7.50%
Convertible notes, conversion price (in Dollars per Share)								$ 5.48			$ 5.48					$ 6.25		$ 6.25						$ 7.50
Debt instrument, convertible, remaining amortization period (in Duration)											1 year 1 month							1 year 4 months
Debt instrument, convertible, conversion threshold (in Dollars per Share)								$ 7.12	$ 7.23							$ 8.13	$ 8.26
Debt instrument, convertible, if-converted value											97,400,000					54,300,000
Net proceeds from the issuance of convertible notes			0	0	149,712,000										149,700,000
Convertible notes repurchase price as a percentage of principal (in Percent)															100.00%
Debt Instrument, Face Amount								180,000,000			180,000,000	179,000,000	180,000,000			155,250,000		155,250,000	155,250,000								0	0
Conversion Rate per $1,000 Principal Amount (in Ratio)								182.598								159.9165
Number of hedge counterparties (in Counterparties)																					2
Purchased call options cost			0	0	(20,765,000)															7,200,000	20,800,000
Number of shares of common stock covered by the purchased call options purchased (in Shares)																							27,500,000
Proceeds from issuance of warrants			0	0	10,868,000																	10,900,000	10,900,000
Debt conversion, shares issued (in Shares)																								1,900,000
Gain on conversion of convertible notes			0	0	(766,000)																				1,100,000
Debt instrument, increase, additional borrowings			75,000,000	0							1,000,000	176,679,000						0	0						88,000,000						0	0		75,000,000	0
Securitization of royalties (in percent)																																	60.00%
Securitization of royalties (in years)																																	5 years
Short-term Debt																																				$ 75,000,000