CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, unless otherwise specified	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interests [Member]	Total
Balance at Dec. 25, 2011	$ 2,143	$ 1,443,484	$ (843,945)	$ (46,070)	$ 2,818	$ 558,430
Balance, (in shares) at Dec. 25, 2011	214,282
Comprehensive income:
Net income	0	0	39,173	0	425	39,598
Other comprehensive income, net of tax:
Net unrealized holding gains on available-for-sale securities, net of tax of $0	0	0	0	5	0	5
Gains associated with pension and other postretirement benefit obligations, net of tax of $0	0	0	0	415	0	415
Total other comprehensive income, net of tax						420
Total comprehensive income						40,018
Issuance of common stock	444	197,935	0	0	0	198,379
Issuance of common stock (in shares)	44,444
Share-based compensation plans:
Common stock issued under compensation plans	2	0	0	0	0	2
Common stock issued under compensation plans (in shares)	200
Requisite service period recognition	0	147	0	0	0	147
Balance at Mar. 25, 2012	2,589	1,641,566	(804,772)	(45,650)	3,243	796,976
Balance, (in shares) at Mar. 25, 2012	258,926
Balance at Dec. 30, 2012	2,590	1,642,003	(669,711)	(68,511)	2,626	908,997
Balance, (in shares) at Dec. 30, 2012	258,999
Comprehensive income:
Net income	0	0	54,582	0	(354)	54,228
Other comprehensive income, net of tax:
Net unrealized holding gains on available-for-sale securities, net of tax of $0						0
Gains associated with pension and other postretirement benefit obligations, net of tax of $0	0	0	0	10,410	0	10,410
Total other comprehensive income, net of tax						10,410
Total comprehensive income						64,638
Share-based compensation plans:
Common stock issued under compensation plans	0	0	0	0	0	0
Common stock issued under compensation plans (in shares)	30
Requisite service period recognition	0	548	0	0	0	548
Balance at Mar. 31, 2013	$ 2,590	$ 1,642,551	$ (615,129)	$ (58,101)	$ 2,272	$ 974,183
Balance, (in shares) at Mar. 31, 2013	259,029