Components of Selected Balance Sheet Accounts (Parenthetical) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Compensation	$ 8,584,000	[1],[2]	$ 6,853,000	[1],[2]
Unfunded Defined Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Defined benefit pension and postretirement health care plans	3,000,000		5,100,000
Pension and postretirement benefit expense	300,000		300,000		400,000
Defined Contribution Retirement Plan
Defined Benefit Plan Disclosure [Line Items]
Compensation	200,000		200,000
Recognized expense	$ 1,000,000		$ 900,000		$ 1,200,000

[1] Includes the combined unfunded benefit obligations under our defined benefit pension and postretirement health care plans of $3.0 million and $5.1 million as of December 31, 2013 and 2012. The expense recognized with respect to these plans was $0.3 million, $0.3 million and $0.4 million for the years ended December 31, 2013, 2012 and 2011, respectively.

[2] Includes employer matching obligations under our defined contribution retirement plan of $0.2 million and $0.2 million as of December 31, 2013 and 2012, respectively. The expense recognized with respect to this plan was $1.0 million, $0.9 million and $1.2 million for the years ended December 31, 2013, 2012 and 2011, respectively.