Subsequent events (Details) (USD $) In Thousands, except Share data, unless otherwise specified		1 Months Ended		0 Months Ended														0 Months Ended
	Sep. 30, 2012 item	Feb. 28, 2012 KCPC	Oct. 02, 2012 Subsequent event item	Oct. 25, 2012 Subsequent event Interest Rate Swaps	Oct. 02, 2012 Subsequent event KCPC item	Oct. 02, 2012 Subsequent event KCPC Kohlberg, Lubert-Adler and Versa	Oct. 02, 2012 Subsequent event KCPC Maximum	Oct. 02, 2012 Subsequent event KCPC Minimum Kohlberg, Lubert-Adler and Versa	Oct. 02, 2012 Subsequent event KCPC Senior Credit Facility Bank of America as Administrative Agent	Oct. 02, 2012 Subsequent event KCPC Senior Credit Facility Bank of America as Administrative Agent Maximum	Oct. 02, 2012 Subsequent event KCPC Senior Credit Facility Bank of America as Administrative Agent Minimum	Oct. 02, 2012 Subsequent event KCPC Senior Credit Facility Bank of America as Administrative Agent Federal funds rate	Oct. 02, 2012 Subsequent event KCPC Senior Credit Facility Bank of America as Administrative Agent Bank of America prime rate	Oct. 02, 2012 Subsequent event KCPC Senior Credit Facility Bank of America as Administrative Agent LIBOR	Oct. 02, 2012 Subsequent event KCPC Senior Credit Facility Bank of America as Administrative Agent Base Rate	Oct. 02, 2012 Subsequent event KCPC Senior Credit Facility Bank of America as Administrative Agent LIBOR for base rate	Oct. 02, 2012 Subsequent event KCPC Revolving credit facility Bank of America as Administrative Agent	Oct. 02, 2012 Subsequent event KCPC Revolving credit facility Prior Credit Agreement	Oct. 02, 2012 Subsequent event KCPC Letter of credit facility Bank of America as Administrative Agent	Oct. 02, 2012 Subsequent event KCPC Term loan facility Bank of America as Administrative Agent
Subsequent events
Common stock issued (in shares)		6,161,334			6,161,334
Cash consideration to be paid on the third anniversary of the closing of the Merger					$ 27,000
Number of directors on Company Board	5		8
Number of additional directors					3
Credit Agreement
Maximum borrowing capacity									450,000								200,000		100,000	250,000
Amortization of principal in the first year																				22,500
Amortization of principal in the second year																				22,500
Amortization of principal in the third year																				30,000
Amortization of principal in the fourth year																				30,000
Amortization of principal in the fifth year																				37,500
Amount borrowed																	72,800
Period of total debt to EBITDA ratio									12 months
Variable rate basis												federal funds rate	Bank of America prime rate	LIBOR	base rate	LIBOR
Interest rate margin on variable rate basis (as a percent)												0.50%				1.00%
Total debt to EBITDA ratio that is required to be maintained										4.5
Fixed charge coverage ratio that is required to be maintained											1.25
Losses on the extinguishment of debt related to unamortized other comprehensive income on the interest rate cap																		428
Losses on the extinguishment of debt related to debt issuance costs																		534
Interest Rate Swap Agreements
Variable rate basis				one-month LIBOR
Fixed rate (as a percent)				0.7525%
Aggregate starting notional amount				$ 150,000
Registration Rights Agreement
Period within which a shelf registration statement is required to be filed							6 months
Additional Closing Agreements
Period for third party shares to be counted as present and vote as agreed at any meeting of stockholders						3 years
Period for third party shares to be counted as present and vote per Board recommendation						2 years
Percentage of stock ownership for third party shares to be counted as present and vote as agreed at any meeting of stockholders								10.00%
Standstill period for the third party						4 years