CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interests [Member]
Balance at Dec. 25, 2011	$ 558,430	$ 2,143	$ 1,443,484	$ (843,945)	$ (46,070)	$ 2,818
Balance, shares at Dec. 25, 2011		214,282
Comprehensive income:
Net income (loss)	108,751			108,531		220
Other comprehensive income (loss), net of tax:
Unrealized holding gains on available-for-sale securities, net of tax
Gains (losses) associated with pension and other postretirement benefit obligations, net of tax of $0	(11,025)				(11,025)
Total other comprehensive income (loss), net of tax	(11,025)
Comprehensive income	97,726
Issuance of common stock	198,282	444	197,838
Issuance of common stock (in shares)		44,444
Share-based compensation plans:
Common stock issued under compensation plans	2	2
Common stock issued under compensation plans (in shares)		200
Requisite service period recognition	297		297
Balance at Jun. 24, 2012	854,737	2,589	1,641,619	(735,414)	(57,095)	3,038
Balance, shares at Jun. 24, 2012		258,926
Balance at Dec. 30, 2012	908,997	2,590	1,642,003	(669,711)	(68,511)	2,626
Balance, shares at Dec. 30, 2012		258,999
Comprehensive income:
Net income (loss)	245,019			245,287		(268)
Other comprehensive income (loss), net of tax:
Unrealized holding gains on available-for-sale securities, net of tax
Gains (losses) associated with pension and other postretirement benefit obligations, net of tax of $0	35,801				35,801
Total other comprehensive income (loss), net of tax	35,801
Comprehensive income	280,820
Share-based compensation plans:
Common stock issued under compensation plans
Common stock issued under compensation plans (in shares)		30
Requisite service period recognition	1,603		1,603
Balance at Jun. 30, 2013	$ 1,191,420	$ 2,590	$ 1,643,606	$ (424,424)	$ (32,710)	$ 2,358
Balance, shares at Jun. 30, 2013		259,029