Debt - Additional Information (Detail) (USD $) In Millions, unless otherwise specified		6 Months Ended				6 Months Ended										6 Months Ended
	Jun. 30, 2013	Jun. 30, 2013 Procurian term loan	Jun. 30, 2013 Interest Rate Swap Hedge	Jun. 30, 2013 PNC Bank Revolving Credit Facility	Jun. 30, 2013 PNC Bank Letter of Credit	Jun. 30, 2013 PNC Bank Procurian term loan	Jun. 30, 2013 PNC Bank Procurian term loan Minimum	Jun. 30, 2013 PNC Bank Procurian term loan Maximum	Jun. 30, 2013 PNC Bank Interest Rate Swap Hedge	Jun. 30, 2013 Horizon	Dec. 31, 2012 Horizon	Jun. 30, 2013 Horizon Revolving Credit Facility	Oct. 22, 2012 Horizon Revolving Credit Facility	Jun. 30, 2013 Horizon Term Loan Credit Facility	Oct. 22, 2012 Horizon Term Loan Credit Facility	Jun. 30, 2013 Venture Bank	Jun. 30, 2013 Venture Bank Minimum	Jun. 30, 2013 Venture Bank Revolving Credit Facility	Dec. 31, 2012 Venture Bank Revolving Credit Facility	Nov. 30, 2012 Venture Bank Revolving Credit Facility	Jun. 30, 2013 Venture Bank Term Loan Credit Facility	Dec. 31, 2012 Venture Bank Term Loan Credit Facility	Nov. 30, 2012 Venture Bank Term Loan Credit Facility
Line Of Credit Facility [Line Items]
Extended date of mature, before				Aug. 02, 2015
Line of credit facility, unused capacity, commitment fee				0.25%
Line of credit	$ 25.0			$ 15.0	$ 5.0								$ 5.0		$ 5.0					$ 2.0			$ 2.5
Balance term loan	13.0
Additional borrowing entitled	12.0
Federal fund open rate						Federal Funds Open Rates plus 0.5%
Federal fund open rate percentage						0.50%
Debt instrument basis spread on variable rate sum of daily LIBOR rate						Sum of the daily LIBOR rate plus 1.0%,
Daily LIBOR rate percentage						1.00%
Debt instrument basis spread on variable rate daily to six month LIBOR rate						Daily to six month LIBOR rate plus a margin ranging from 1.5% to 2.0%,
Six Month LIBOR rate percentage							2.00%	1.50%
Line of credit facility, periodic payment, principal						0.4
Annual interest rate						Monthly
Effective interest rate being paid		1.94%
Term loan was effectively converted to a fixed interest rate									50.00%
Term loan was effectively converted to a fixed interest fate interest rate									1.34%
Interest rate swap hedge agreement			10.0
Fair value of line of credit										9.9	9.8
Loan interest rate										11.65%
Loans maturity date										May 01, 2016						Nov. 30, 2017
Line of credit outstanding amount												$ 5.0		$ 5.0				$ 1.4	$ 0		$ 2.5	$ 2.5
Prime rate																Prime rate plus 2.0%
Prime rate percentage																2.00%	5.50%