Debt (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended			3 Months Ended			3 Months Ended								0 Months Ended															0 Months Ended
	Mar. 31, 2013 Term loans	Mar. 31, 2013 Term loans LIBOR	Mar. 31, 2013 Term loans Index Rate	Mar. 31, 2013 Revolving credit facility	Mar. 31, 2013 Revolving credit facility LIBOR	Mar. 31, 2013 Revolving credit facility Index Rate	Mar. 31, 2013 Senior Credit Facilities	Mar. 31, 2013 Senior Credit Facilities Through June 30, 2013	Mar. 31, 2013 Senior Credit Facilities Through December 31, 2013	Mar. 31, 2013 Senior Credit Facilities Through September 30, 2014	Mar. 31, 2013 Senior Credit Facilities Through March 31, 2015	Mar. 31, 2013 Senior Credit Facilities After March 31, 2015	Mar. 31, 2013 August 2012 Amendment of Senior Credit Facilities	Mar. 31, 2013 PBL	May 03, 2013 Subsequent event Senior Credit Facilities	May 03, 2013 Subsequent event Senior Credit Facilities Through December 31, 2013	May 03, 2013 Subsequent event Senior Credit Facilities Through September 30, 2013	May 03, 2013 Subsequent event Senior Credit Facilities After December 31, 2013	May 03, 2013 Subsequent event Senior Credit Facilities Through March 31, 2014	May 03, 2013 Subsequent event Senior Credit Facilities Through June 30, 2014	May 03, 2013 Subsequent event Senior Credit Facilities Through December 31, 2014	May 03, 2013 Subsequent event Senior Credit Facilities Through June 30, 2015	May 03, 2013 Subsequent event Senior Credit Facilities Through September 30, 2015	May 03, 2013 Subsequent event Senior Credit Facilities Through December 31, 2015	May 03, 2013 Subsequent event Senior Credit Facilities After December 31, 2015	May 03, 2013 Subsequent event Maximum leverage ratio between 4.00 and 4.50 Senior Credit Facilities LIBOR	May 03, 2013 Subsequent event Maximum leverage ratio between 4.00 and 4.50 Senior Credit Facilities Index Rate	May 03, 2013 Subsequent event Maximum leverage ratio greater than 4.50 Senior Credit Facilities LIBOR	May 03, 2013 Subsequent event Maximum leverage ratio greater than 4.50 Senior Credit Facilities Index Rate	May 03, 2013 Minimum Subsequent event Maximum leverage ratio between 4.00 and 4.50 Senior Credit Facilities	May 03, 2013 Maximum Subsequent event Maximum leverage ratio between 4.00 and 4.50 Senior Credit Facilities	May 03, 2013 Maximum Subsequent event Maximum leverage ratio greater than 4.50 Senior Credit Facilities
Debt Instrument [Line Items]
Fees and transaction costs incurred													$ 1.2		$ 1.6
Maximum borrowings				400.0
Additional borrowings available				56.8
Spread on variable rate (percentage)		2.50%	1.50%		2.50%	1.50%																				3.00%	2.00%	3.50%	2.50%
Debt Covenant Interest Terms Maximum Leverage Ratio Requirements																														4.00	4.50	4.50
Maturity date				Aug. 31, 2016
Quarterly principal payment required	3.8
Final payment due on maturity date	225.0
Fixed charge coverage ratio							1.15									1.10	1.05	1.15
Maximum leverage ratio								4.00	3.75	3.50	3.25	3.00				4.60			4.35	4.25	4.00	3.75	3.50	3.25	3.00
Percentage of pledge of stock as additional collateral							65.00%
Debt assumed on acquisition														13.5
Capital lease obligations														$ 0.6