Long-term Debt - Senior Convertible Notes - Narrative (Details) (Director [Member], Convertible Debt [Member], Senior Convertible Note [Member], USD $) Share data in Millions, except Per Share data, unless otherwise specified	0 Months Ended	1 Months Ended
	May 28, 2012	Apr. 30, 2013	Nov. 30, 2011
Debt Instrument [Line Items]
Long-term debt due to related party		$ 200,000,000	$ 200,000,000
Interest rate			0.00%
Weighted average price of common stock	$ 111.54
Common stock, shares issued		2.3
Common stock conversion ratio		11.6553
Fair value at conversion		$ 217
Minimum [Member]
Debt Instrument [Line Items]
Trading days prior to conversion date required for conversion	50 days
Maximum [Member]
Debt Instrument [Line Items]
Trading days prior to conversion date required for conversion	65 days