Acquisition (Details) (Central, USD $) In Thousands, except Share data, unless otherwise specified	0 Months Ended	3 Months Ended		6 Months Ended
	Oct. 02, 2012	Jun. 30, 2013	Sep. 30, 2012	Jun. 30, 2013
Central
Acquisitions
Interest acquired (as a percent)	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
Period after which contingent cash consideration subject to adjustments is to be paid	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
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
Present value of cash consideration to be issued			8,943
Total consideration transferred	149,669		149,669
Acquisition and integration related costs included in general and administrative expenses		$ 3,093		$ 7,317