Components of Selected Balance Sheet Accounts (Parenthetical) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Schedule of Condensed Consolidating Balance Sheets [Line Items]
Compensation	$ 5,186,000	[1],[2]	$ 9,631,000	[1],[2]
Unfunded Defined Benefit Plan
Schedule of Condensed Consolidating Balance Sheets [Line Items]
Defined benefit pension and postretirement health care plans	5,400,000		5,400,000
Pension and postretirement benefit expense	400,000		600,000		600,000
Defined Contribution Retirement Plan
Schedule of Condensed Consolidating Balance Sheets [Line Items]
Compensation	300,000		300,000
Recognized expense	$ 1,200,000		$ 1,700,000		$ 2,300,000

[1] Includes the combined unfunded benefit obligations under the Company's defined benefit pension and postretirement health care plans of $5.4 million as of December 31, 2011 and 2010. The expense recognized with respect to these plans was $0.4 million, $0.6 million and $0.6 million, for the years ended December 31, 2011, 2010 and 2009, respectively.

[2] Includes employer matching obligations under the Company's defined contribution retirement plan of $0.3 million as of December 31, 2011 and 2010. The expense recognized with respect to this plan was $1.2 million, $1.7 million and $2.3 million for the years ended December 31, 2011, 2010 and 2009, respectively.