Acquisitions (Details) (USD $) In Thousands, except Share data, unless otherwise specified	0 Months Ended	3 Months Ended	12 Months Ended
	Oct. 02, 2012	Sep. 30, 2012	Dec. 31, 2013	Dec. 31, 2012
Fair value of the final consideration transferred
Stock consideration				$ 140,726
Merger costs related to the Credit Agreement, recognized as discount to borrowings			3,553
KCPC
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
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		(298,386)
Threshold		285,000
Excess over the threshold		(13,386)
Indemnification of certain defined adverse consequences, net		(5,817)
Cash consideration payable in three years	27,000	27,000
Settled cash consideration		7,797
Fair value of the final consideration transferred
Stock consideration		140,726
Total consideration transferred	149,669	147,058
Acquisition and integration related costs included in general and administrative expenses			10,918	28,036
Merger costs related to obtaining the Credit Agreement				10,332
Merger costs related to the Credit Agreement, recognized as debt issuance costs included in other assets net				5,149
Merger costs related to the Credit Agreement, recognized as discount to borrowings				5,183
KCPC | Fair Value
Settlement reducing cash consideration
Present value of cash consideration to be issued		8,943	6,332
Fair value of the final consideration transferred
Present value of cash consideration to be issued		$ 8,943	$ 6,332