Acquisition (Details) (KCPC, USD $)	0 Months Ended	3 Months Ended
	Oct. 02, 2012	Mar. 31, 2014	Mar. 31, 2013	Sep. 30, 2012
Acquisitions
Interest acquired (as a percent)	100.00%
Common stock issued (in shares)	6,161,332
Assumption of debt, net of cash acquired	$ 217,675,000
Contingent cash consideration	27,000,000			27,000,000
Period after which contingent cash consideration to be paid	3 years
Price of share at which former stockholders of acquiree can elect to pay applicable amount (in dollars per share)	$ 23.64
Minimum cash consideration to cover capped indemnities	17,000
Settlement reducing cash consideration
Period in which reduction in cash consideration payable for the seller's indemnification made				3 years
Central Net Debt Working Capital as defined in the Merger Agreement				(298,729,000)
Threshold				285,000,000
Excess over the threshold				(13,729,000)
Indemnification of certain defined adverse consequences, net				(6,237,000)
Cash consideration payable in three years	27,000,000			27,000,000
Settled cash consideration				7,034,000
Fair value of the final consideration transferred
Stock consideration				140,726,000
Total consideration transferred				146,666,000
Acquisition and integration related costs included in general and administrative expenses		1,505,000	4,213,000
Fair Value
Settlement reducing cash consideration
Present value of cash consideration to be issued		5,940,000		8,943,000
Fair value of the final consideration transferred
Present value of cash consideration to be issued		$ 5,940,000		$ 8,943,000