Fair Value Measurements (Detail) (USD $)	12 Months Ended						12 Months Ended					1 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Jun. 11, 2013	Jun. 30, 2013 3.75% Unsecured Convertible Subordinated Debentures Due In 2026	Nov. 30, 2012 3.75% Unsecured Convertible Subordinated Debentures Due In 2026	Dec. 31, 2013 School Specialties	Jun. 11, 2013 School Specialties	Nov. 30, 2012 Marketable Securities	Dec. 31, 2013 Senior Notes Convertible Senior Subordinted Notes Due 2023	Dec. 31, 2012 Senior Notes Convertible Senior Subordinted Notes Due 2023	Jan. 31, 2014 Subsequent Event Senior Notes Convertible Senior Subordinted Notes Due 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment, cost					$ 9,800,000	$ 6,000,000
Face amount									11,900,000
Interest rate (as a percent)										0.75%	0.75%
Debtor-in-possession financing, amount arranged							21,300,000
Shares received in exchange for convertible debentures (in shares)								26,457
Debtor in possession, cash received in exchange for investment in loan								17,500,000
Shares received in exchange for investment in loan (in shares)				49,136
Debtor in possession, fair value of shares received (in dollars per share)				$ 109
Debtor in possession, gain on disposal of investment in loan							3,200,000
Debtor in possession, loss on disposal of loan							1,600,000
Convertible notes payable, current	346,000	346,000								300,000	300,000
Cash payment for debt redemption	$ 15,500,000	$ 3,000,000	$ 0									$ 300,000