Debt - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012
Extinguishment of Debt [Line Items]
Asset based senior secured revolving credit	$ 120.0
Credit facility maturity date	Dec. 21, 2017
Revolving credit borrowing	62.4	59.8	62.5
Weighted average interest rate	2.79%
Letters of credit outstanding	3.6
Additional committed borrowing capacity	50.7
Capital lease and other obligations	0.9
FCCR testing threshold	14.0
FCCR excess availability	50.7
Minimum [Member]
Extinguishment of Debt [Line Items]
Unused commitment fees	0.30%
Fixed charge coverage ratio	10.0
FCCR	1.25%
Line of credit facility current borrowing capacity	10.0
Maximum [Member]
Extinguishment of Debt [Line Items]
Unused commitment fees	0.375%
Fixed charge coverage ratio	15.0
Line of credit facility current borrowing capacity	15.0
Amended amortization on real estate component of borrowing base [Member]
Extinguishment of Debt [Line Items]
Amortization on real estate component of borrowing base	12 years 6 months
Revolving credit facility [Member]
Extinguishment of Debt [Line Items]
Revolving credit borrowing	$ 61.5	$ 59.1	$ 62.4