Fair Value Measurements Fair Value Measurements - Debt Derivatives (Details) (Bond Hedge [Member], USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2013		Dec. 30, 2012
Statement [Line Items]
Stock price	$ 11.54	[1]	$ 5.49	[1]
Interest rate	0.41%	[1]	0.40%	[1]
Stock volatility	55.60%	[1]	59.90%	[1]
Credit risk adjustment	1.13%	[1]	1.07%	[1]
Maturity date	Feb. 18, 2015	[1]	Feb. 18, 2015	[1]
4.50% Debentures [Member]
Fair Value Disclosures [Abstract]
Option Indexed to Issuer's Equity, Strike Price	22.53	[1]	22.53	[1]

[1] The valuation model utilizes these inputs to value the right but not the obligation to purchase one share at $22.53. The Company utilized a Black-Scholes valuation model to value the 4.50% Bond Hedge and embedded cash conversion option. The underlying input assumptions were determined as follows:(i)Stock price. The closing price of the Company's common stock on the last trading day of the quarter.(ii)Exercise price. The exercise price of the 4.50% Bond Hedge and the embedded cash conversion option.(iii)Interest rate. The Treasury Strip rate associated with the life of the 4.50% Bond Hedge and the embedded cash conversion option.(iv)Stock volatility. The volatility of the Company's common stock over the life of the 4.50% Bond Hedge and the embedded cash conversion option.(v)Credit risk adjustment. Represents the weighted average of the credit default swap rate of the counterparties.