Debt - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	1 Months Ended	6 Months Ended
	May 31, 2014	Jun. 30, 2014	Dec. 31, 2013	Jun. 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		$ 88.9	$ 62.0	$ 69.5
Weighted average interest rate		2.37%
Letters of credit outstanding		3.5
Additional committed borrowing capacity		42.1
Unused commitment fees		0.25%
Capital lease and other obligations		1.6
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
Revolving credit facility [Member]
Line of Credit Facility [Line Items]
Revolving credit borrowing		$ 87.3
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