Acquisition (Details) (KCPC, USD $) In Thousands, except Share data, unless otherwise specified	0 Months Ended	3 Months Ended			9 Months Ended
	Oct. 02, 2012	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2014	Sep. 30, 2013
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 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
Cash consideration payable in three years from the acquisition date, pursuant to the Merger Agreement and prior to Central Net Debt Working Capital and indemnification of certain defined adverse consequences, net	27,000			27,000
Net Debt Working Capital as defined in the Merger Agreement				(296,399)
Threshold of Net Debt Working Capital, pursuant to the Merger Agreement				285,000
Excess over the threshold of Net Debt Working Capital				(11,399)
Indemnification of certain defined adverse consequences, net				(14,122)
Indemnification of cost pursuant to merger agreement		80.00%
Settled cash consideration				1,479
Acquisition and integration related costs included in general and administrative expenses		2,989	1,893		5,031	9,210
Fair Value
Settlement reducing cash consideration
Present value of cash consideration liability to be issued		$ 1,279			$ 1,279