Revolving Credit Agreement (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				1 Months Ended		1 Months Ended	3 Months Ended			3 Months Ended		3 Months Ended				3 Months Ended					3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Dec. 20, 2012	Sep. 30, 2012	Sep. 30, 2012 Second amended credit agreement [Member]	Sep. 28, 2012 Second amended credit agreement [Member]	Sep. 30, 2012 Third amended credit agreement [Member]	Mar. 31, 2013 Third amended credit agreement [Member]	Sep. 28, 2012 Third amended credit agreement [Member]	May 09, 2013 Subsequent Event [Member]	Mar. 31, 2013 Base rate loan [Member]	Mar. 31, 2013 LIBOR rate [Member]	Mar. 31, 2013 Eurodollar Loan [Member]	Mar. 31, 2013 Maximum [Member]	Dec. 20, 2012 Maximum [Member]	Sep. 28, 2012 Maximum [Member] Third amended credit agreement [Member]	Mar. 31, 2013 Maximum [Member] Base rate loan [Member]	Mar. 31, 2013 Maximum [Member] Eurodollar Loan [Member]	Mar. 31, 2013 Minimum [Member]	Dec. 20, 2012 Minimum [Member]	Sep. 28, 2012 Minimum [Member] Third amended credit agreement [Member]	Mar. 31, 2013 Minimum [Member] Base rate loan [Member]	Mar. 31, 2013 Minimum [Member] Eurodollar Loan [Member]
Revolving Credit Agreement (Textual) [Abstract]
Senior secured revolving credit maximum facility						$ 400.0			$ 500.0
Borrowing base	255.0														215.0	200.0				200.0	125.0
Conforming borrowing base	220.0		180.0						165.0
Borrowed under credit agreement	205.0									230.0
Company amended and restated its senior secured revolving credit agreement					2012-09-28
Conforming borrowing base date								Dec. 31, 2013
Net cash proceeds from secondary public offering							25.0
Conforming borrowing base description								The borrowing base will automatically be reduced to an amount equal to the conforming borrowing base on the earlier of (i) December 31, 2013 or (ii) the closing of a secondary public offering of equity interests by the Company that results in net cash proceeds to the Company in an amount greater than or equal to $25 million.
Outstanding letters of credit	1.3									1.3
Borrowings interest rate												1.00%
Additional interest rate																	2.25%	3.25%				0.75%	1.75%
Credit facility fee														0.50%					0.375%
Borrowings interest rate description											If the Company borrows funds as a base rate loan, such borrowings will bear interest at a rate equal to the higher of (i) the prime rate for such day or (ii) the Federal Funds Effective Rate on such day, plus 0.50% or (iii) the daily adjusting LIBOR rate plus 1.0% plus, in each case, an amount from 0.75% to 2.25% of such outstanding loan depending on the level of borrowings under the Agreement		If the Company borrows funds as a Eurodollar loan, such borrowings will bear interest at a rate equal to (i) the quotient obtained by dividing (A) the LIBOR rate by (B) a percentage equal to 100% minus the maximum rate during such interest calculation period at which RBC is required to maintain reserves on Eurocurrency Liabilities (as defined in Regulation D of the Board of Governors of the Federal Reserve System) plus (ii) an amount from 1.75% to 3.25% of such outstanding loan depending on the level of borrowings under the Agreement.
Revolving Credit Agreement (Additional Textual) [Abstract]
Repay deficit in agreement Period	6 months
Additional deferred loan cost	0.3	0.1		0.8
Deferred Loan Costs	1.7
Additional borrowings for working capital requirements	$ 25.0	$ 150.0
Outstanding borrowings bore interest effective rate	3.60%
Credit Agreement, maturity date	Dec. 29, 2016
The borrowing base under the Credit Agreement determined	semi-annually
Federal Funds Effective Plus Rate	0.50%
Percentage of reserves required to maintain	100.00%
Total debt outstanding to EBITDA	4.0
Current ratio	1.0