Debt - Additional Information (Detail) (RMCO, USD $)	3 Months Ended	9 Months Ended									1 Months Ended			1 Months Ended					3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 2013 Credit Facility	Sep. 30, 2012 2013 Credit Facility	Apr. 16, 2010 Senior Secured Term Loan Credit Facility	Sep. 30, 2013 Senior Secured Revolving Credit Facility	Dec. 31, 2012 Senior Secured Revolving Credit Facility	Apr. 16, 2010 Senior Secured Revolving Credit Facility	Dec. 31, 2012 Amended Senior Secured Credit Facility	Jul. 31, 2013 2013 Term Loan Facility	Sep. 30, 2013 2013 Term Loan Facility	Sep. 30, 2013 2013 Revolving Loan Facility	Jul. 31, 2013 LIBOR Maximum	Jul. 31, 2013 ABR Member	Jul. 31, 2013 Federal Funds Rate Plus	Jul. 31, 2013 Eurodollar Rate Plus	Jul. 31, 2013 Eurodollar Rate Plus Maximum	Sep. 30, 2013 2013 Credit Facility	Sep. 30, 2013 2013 Credit Facility	Sep. 30, 2013 2013 Credit Facility Fair Value, Inputs, Level 2	Dec. 31, 2012 2013 Credit Facility Fair Value, Inputs, Level 2
Debt Instrument [Line Items]
Credit Facility									$ 10,000,000				$ 10,000,000
Amended Credit Facility						215,000,000				45,000,000		230,000,000
Interest rate terms											Interest rates with respect to the term and revolving loans are based, at the Company’s option, on (a) adjusted LIBOR, provided that LIBOR shall be no less than 1% plus a maximum applicable margin of 3% or (b) ABR, provided that ABR shall be no less than 2%, which is equal to the greater of (1) JPMorgan Chase Bank, N.A.’s prime rate; (2) the Federal Funds Effective Rate plus 0.5% or (3) calculated Eurodollar Rate plus 1.0%, plus a maximum applicable margin of 2%. The applicable margin will be adjusted quarterly beginning in the first quarter of 2014 based on the Company’s total leverage ratio as defined in the 2013 Senior Secured Credit Facility.
Interest rate															2.00%	0.50%	1.00%
Applicable margin														3.00%				2.00%
Loss on early extinguishment of debt	(1,664,000)	(1,798,000)	(136,000)	134,000	136,000														1,664,000	1,664,000
Debt issuance costs		(1,301,000)																		3,219,000
Debt Instrument, issuance cost																			1,301,000	1,301,000
Debt Instrument, expense incurred																				1,918,000
Excess Cash Flow payment		15,000,000
Principal payments are due on quarterly		575,000
Debt Instrument, Maturity Date		Jul. 31, 2020
Principal Excess Cash Flow prepayments	8,000,000	6,123,500
Credit Facility, fair value																					229,712,000	233,046,000
Credit Facility				$ 228,957,000			$ 228,957,000	$ 232,326,000
Revolving loan facility commitment fee on average daily amount of unused portion		0.50%