Long-Term Debt (Details Textual) (USD $) In Millions, unless otherwise specified	1 Months Ended	9 Months Ended		1 Months Ended	3 Months Ended	9 Months Ended		1 Months Ended	3 Months Ended	9 Months Ended				9 Months Ended				9 Months Ended			1 Months Ended	9 Months Ended
	Feb. 28, 2011	Jun. 30, 2012	Sep. 30, 2011	Feb. 28, 2011 Term Loan [Member]	Dec. 31, 2011 Term Loan [Member]	Jun. 30, 2012 Term Loan [Member]	Feb. 09, 2011 Term Loan [Member]	Feb. 28, 2011 Senior revolver, due February 9, 2016; quarterly cash interest payments at a variable interest rate [Member]	Dec. 31, 2011 Senior revolver, due February 9, 2016; quarterly cash interest payments at a variable interest rate [Member]	Jun. 30, 2012 Senior revolver, due February 9, 2016; quarterly cash interest payments at a variable interest rate [Member]	Feb. 09, 2011 Senior revolver, due February 9, 2016; quarterly cash interest payments at a variable interest rate [Member]	Jun. 30, 2012 Senior revolver, due February 9, 2016; quarterly cash interest payments at a variable interest rate [Member] Standby Letters of Credit [Member]	Jun. 30, 2012 Senior revolver, due February 9, 2016; quarterly cash interest payments at a variable interest rate [Member] Letter of Credit [Member]	Jun. 30, 2012 Covenants [Member]	Jun. 30, 2012 Derivatives [Member]	Sep. 30, 2011 Derivatives [Member]	Mar. 31, 2011 Derivatives [Member]	Jun. 30, 2012 Interest Rate Swap [Member]	Feb. 09, 2011 Letter of Credit [Member]	Jun. 30, 2012 Eurodollar Future [Member]	Feb. 28, 2011 Senior notes [Member]	Jun. 30, 2012 Senior notes [Member]	Dec. 31, 2011 Senior notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 400.0					$ 530.0				$ 75.0										$ 250.0
Amount deposited in cash collateral account in support of issuance of letters of credit																			50.0
Debt instruments in stated percentage																							12.50%
Debt instrument, issuance date						Feb. 09, 2017			Feb. 09, 2016													Feb. 15, 2018
Price of term loan issued of its face value						98.50%
Amortization rate of price of term loan was issued of its face value						1.00%
Provision for repayment of outstanding term loan					0 to 50%
Term loan effective interest rate						7.00%	0.50%										7.80%			1.00%
Line of Credit Facility Basis Spread on Variable Rate Euro Dollar Option One																		4.25%		5.25%
Variable Interest rate on term loan						The variable interest rate on the term loan is equal to (i) a rate equal to the greater of (a) the prime rate, (b) the federal funds rate plus 1/2 of 1% and (c) the Eurodollar rate for an interest period of one-month beginning on such day plus 100 basis points, plus 4.25%; or (ii) the Eurodollar rate (provided that the rate shall not be less than 1.75% per annum), plus 5.25%, at the Company’s option.
Drawings										494.1
Repayment										490.6
Outstanding Borrowings										3.5		38.4
Availability of Borrowings										71.5
Maximum limit of Letters of credit can be issued under the Company s institutional letter of credit facility													50.0
Rate of Price of their face value																					97.737%
Net Proceeds																					244.3
The net proceeds were reduced by an initial purchasers discount																					5.6
Maximum limit of dividends pay to NMH Holdings, LLC ("Parent")														15.0
Interest rate swap in a notional amount																	400.0
Margin on base rate (as a percent) for Interest Rate Swap															1.75%					1.75%
Term loan rate as per the swap																	2.50%
Applicable margin rate on Company's term loan															5.25%
Fair Value of Swap Agreement		6.1	6.7												3.6	4.0
Refinancing activities duration				6 years				5 years
Derivative maturity date																		Sep. 30, 2014
Long-Term Debt (Textual) [Abstract]
Refinancing Expenses	19.3
Tender Premium and Consent fee	10.8
Repurchase of Senior Subordinated Notes due 2014	11.25%
Deferred Financing Costs Related to the Prior Indebtedness	7.9
Transaction Cost	$ 0.6
Line of Credit Facility Basis Spread on Variable Rate Euro Dollar Option One																		4.25%		5.25%
Base Rate on Interest Rate Swap Instrument Derivative		3-month LIBOR