Net Income per Share (Narrative) (Detail) - USD ($) $ in Thousands					3 Months Ended		6 Months Ended
	May 02, 2015	Feb. 18, 2015	Oct. 20, 2014	Feb. 05, 2014	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015	Nov. 20, 2015	May 01, 2015	Feb. 17, 2015	Nov. 24, 2014	Feb. 12, 2014	Feb. 07, 2014	Feb. 06, 2014	Aug. 01, 2013	Mar. 31, 2012	Feb. 29, 2012	Jan. 31, 2012
Restricted Stock [Member]
Debt Instrument [Line Items]
Antidilutive securities excluded from computation of earnings per share (in Shares)					1,154,000	39,000	1,095,000	38,000
February 2015 Notes [Member]
Debt Instrument [Line Items]
Convertible Notes Payable																		$ 179,000
Convertible notes																	$ 1,000			$ 169,000
Series 2012 Notes [Member]
Debt Instrument [Line Items]
Convertible notes												$ 22,300	$ 26,000		$ 131,700	$ 131,700			$ 10,000
Debt Conversion, Converted Instrument, Shares Issued		1,340,000	1,800,000	20,300,000
May 2015 Notes [Member] [Member]
Debt Instrument [Line Items]
Convertible notes											$ 155,100
February 2018 Notes [Member]
Debt Instrument [Line Items]
Convertible notes					$ 232,847		$ 232,847		$ 228,862	$ 246,400				$ 300,000
February 2018 Notes [Member] | Warrants [Member]
Debt Instrument [Line Items]
Antidilutive securities excluded from computation of earnings per share (in Shares)					23,800,000	29,000,000
February 2018 Notes [Member] | Purchased Call Options [Member]
Debt Instrument [Line Items]
Antidilutive securities excluded from computation of earnings per share (in Shares)					26,900,000	32,700,000
Series 2012 Notes [Member]
Debt Instrument [Line Items]
Debt Conversion, Converted Instrument, Shares Issued	5,200,000