Debt Including Capital Lease Obligations - Carrying and Estimated Fair Value Table (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012		Jun. 30, 2012		Jun. 30, 2013 4.25% Convertible Senior Notes		Dec. 31, 2012 4.25% Convertible Senior Notes		Jun. 30, 2012 4.25% Convertible Senior Notes		Jun. 30, 2013 7.875% Senior Notes Senior notes		Feb. 28, 2013 7.875% Senior Notes Senior notes	Feb. 05, 2013 7.875% Senior Notes Senior notes	Jun. 30, 2012 7.875% Senior Notes Senior notes	Feb. 05, 2013 7.5% Senior Notes Senior notes	Dec. 31, 2012 7.5% Senior Notes Senior notes		Jun. 30, 2012 7.5% Senior Notes Senior notes		Jun. 30, 2013 ABL Term Loan Line of Credit		Dec. 31, 2012 Credit Facility Revolver Line of Credit		Jun. 30, 2012 Credit Facility Revolver Line of Credit		Dec. 31, 2012 Credit Facility Term Loan Line of Credit		Jun. 30, 2012 Credit Facility Term Loan Line of Credit
Debt Instrument [Line Items]
Stated interest rate on debt instrument							4.25%		4.25%		4.25%		7.875%		7.875%	7.875%	7.50%	7.50%	7.50%
Carrying Value							$ 158,400		$ 153,082		$ 148,077		$ 422,028						$ 106,438		$ 106,438		$ 7,125		$ 40,000		$ 20,000		$ 305,250		$ 313,500
Carrying Value - Capital lease obligations	14,250	[1]	755		827
Estimated Fair Value							192,000	[2]	174,000	[2]	145,000	[2]	445,000	[2]					106,000	[2]	106,000	[2]	7,000	[2]	38,000	[2]	19,000	[2]	296,000	[2]	298,000	[2]
Estimated Fair Value - Capital lease obligations	14,000	[1],[2]	700	[2]	800	[2]
Less current portion	(3,078)		(65,008)		(36,777)
Total long-term debt and capital lease obligations	$ 598,725		$ 540,517		$ 552,065

[1] Capital lease obligations include the portion of the borrowings for the salad production and warehousing facility in the Midwest that has been placed into service. The facility is being constructed under a build-to-suit lease with the construction in progress liability included in "Accrued liabilities" and "Other liabilities" on the Condensed Consolidated Balance Sheets and then reclassified to capital lease obligation as the related leased assets are placed into service. See further description of the build-to-suit lease below.

[2] The fair value of the senior notes is based on observable inputs, which include quoted prices for similar assets or liabilities in an active market and market-corroborated inputs (Level 2). All other debt may be traded on the secondary loan market, and the fair value is based on either the last available trading price, if recent, or trading prices of comparable debt (Level 3). See also Note 7 for discussion of fair value.