Long-term Debt - U.S. Bank Debt (Details) (USD $)		3 Months Ended		3 Months Ended						9 Months Ended									12 Months Ended		3 Months Ended		10 Months Ended	3 Months Ended
	Oct. 10, 2012 Revolving credit and term loan facilities [Member]	Dec. 31, 2012 Senior Secured Term Loan B [Member]	Oct. 10, 2012 Senior Secured Term Loan B [Member]	Dec. 31, 2012 Senior Secured Term Loan A [Member]	Dec. 31, 2012 U.S. bank debt and receivables facility [Member]	Dec. 31, 2011 U.S. bank debt and receivables facility [Member]	Dec. 31, 2012 Receivables Facility [Member]	Dec. 17, 2012 Receivables Facility [Member]	Dec. 31, 2011 Receivables Facility [Member]	Oct. 10, 2012 Term loan facility [Member]	Oct. 10, 2012 Revolving credit facility [Member]	Dec. 31, 2012 Revolving credit facility [Member]	Dec. 31, 2011 Revolving credit facility [Member]	Dec. 31, 2012 Letters of credit [Member]	Oct. 10, 2012 Letters of credit [Member]	Dec. 31, 2011 Letters of credit [Member]	Dec. 31, 2012 Maximum [Member] Receivables Facility [Member]	Dec. 17, 2012 Maximum [Member] Receivables Facility [Member]	Dec. 31, 2012 Refinancing of Debt [Member] Revolving credit and term loan facilities [Member]	Dec. 31, 2011 Refinancing of Debt [Member] Revolving credit and term loan facilities [Member]	Dec. 31, 2012 Refinancing of Debt [Member] Senior Secured Term Loan B [Member]	Dec. 31, 2012 Refinancing of Debt [Member] Senior Secured Term Loan A [Member]	Dec. 31, 2012 Refinancing of Debt [Member] Senior Secured Term Loan A [Member]	Dec. 31, 2012 Refinancing of Debt [Member] Senior Secured Term Loan B [Member]	Dec. 31, 2012 Refinancing of Debt [Member] Revolving credit facility [Member]	Dec. 31, 2012 Principal payment, June 2013 through March 2015 [Member] Senior Secured Term Loan A [Member]	Dec. 31, 2012 Principal payment, June 2015 through September 2017 [Member] Senior Secured Term Loan A [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount										$ 217,200,000													$ 200,000,000	$ 200,000,000
Interest rate, LIBOR plus							1.20%		1.50%	3.00%	3.25%						1.35%	1.75%			2.75%	2.00%			2.00%
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum										1.25%											1.00%
Line of Credit Facility, Maximum Borrowing Capacity											125,000,000			75,000,000	50,000,000										250,000,000
Debt Instrument, Maturity Date										Jun. 21, 2017	Jun. 21, 2016												Oct. 11, 2017	Oct. 11, 2019	Oct. 11, 2017
Incremental debt commitments capacity	300,000,000
Term Loan Facility, Required Prepay Premium		1.00%
Term Loan Facility, Required Prepay Portion Under Excess Cash Flow Sweep Provision [Line Items]			5,000,000.00
Letters of Credit Outstanding, Amount														23,300,000		23,900,000
Revolving Credit Facility, Amount Outstanding												0	0
Revolving Credit Facility, Remaining Borrowing Capacity												226,700,000	101,100,000
Debt Instrument, Unused Borrowing Capacity, Amount					230,500,000	158,800,000	51,900,000		57,600,000
Term Loan Facility, Quarterly Principal Payments		500,000																								2,500,000	3,800,000
Term Loan Facility, Principal Payment on Maturity Date		186,000,000		142,500,000
Payments of Debt Extinguishment and Issuance Costs																			6,400,000	6,800,000
Deferred Finance Costs, Noncurrent, Net																			4,500,000	4,400,000
Debt Issuance Cost																			1,900,000	2,400,000
Secured debt, Maximum Borrowing Capacity							105,000,000	90,000,000
Write off of Deferred Debt Issuance Cost																			$ 1,100,000