Debt - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	1 Months Ended	9 Months Ended
	May 31, 2014	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
Line of Credit Facility [Line Items]
Asset based senior secured revolving credit facility extended term	5 years
Credit facility maturity date		May 28, 2019
Revolving credit borrowing		$ 76.3	$ 62.0	$ 62.4
Weighted average interest rate		2.26%
Letters of credit outstanding		3.5
Additional committed borrowing capacity		55.5
Unused commitment fees		0.25%
Capital lease and other obligations		2.0
Fixed charge coverage ratio of credit facility		1.05%
Minimum [Member]
Line of Credit Facility [Line Items]
Asset based senior secured revolving credit	120.0
Fixed charge coverage ratio		12.5
Maximum [Member]
Line of Credit Facility [Line Items]
Asset based senior secured revolving credit	160.0
Fixed charge coverage ratio		20.0
Amended Amortization on Real Estate Component of Borrowing Base [Member]
Line of Credit Facility [Line Items]
Amortization on real estate component of borrowing base		12 years 6 months
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit borrowing		$ 74.3