Acquisitions (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended	0 Months Ended	3 Months Ended	12 Months Ended
	Dec. 31, 2012	Oct. 02, 2012 Central	Sep. 30, 2012 Central	Dec. 31, 2012 Central	Sep. 30, 2012 Central Minimum
Acquisitions
Interest acquired		100.00%
Common stock issued (in shares)		6,161,332
Assumption of debt, net of cash acquired		$ 217,675
Contingent cash consideration		27,000	27,000		17,000
Period after which contingent cash consideration subject to adjustments is to be paid		3 years	3 years
Settlement reducing cash consideration
Central Net Debt Working Capital as defined in the Merger Agreement			(300,546)
Threshold			285,000
Excess over the threshold			(15,546)
Cash consideration payable in three years		27,000	27,000		17,000
Settled cash consideration			11,454
Present value of cash consideration at the acquisition date			8,943
Fair value of the final consideration transferred
Stock consideration	140,726		140,726
Present value of cash consideration to be issued			8,943
Total consideration transferred		149,669
Merger related costs included in general and administrative expenses	26,783			26,783
Merger costs related to the Credit Agreement				10,332
Merger costs related to the Credit Agreement, included in other assets				5,149
Merger costs related to the Credit Agreement, recognized as discount to borrowings				$ 5,183