Financial Commitments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				3 Months Ended
	Mar. 31, 2013 Term Loan	Mar. 31, 2013 Revolving credit facility	Dec. 31, 2012 Revolving credit facility	Mar. 31, 2012 Revolving credit facility	Mar. 31, 2013 Revolving credit facility Minimum	Mar. 31, 2013 Revolving credit facility Maximum	Mar. 31, 2013 Revolving credit facility LIBOR	Mar. 31, 2013 Revolving credit facility LIBOR Minimum	Mar. 31, 2013 Revolving credit facility LIBOR Maximum	Mar. 31, 2013 Revolving credit facility Federal Funds	Mar. 31, 2013 Revolving credit facility Prime rate	Mar. 31, 2013 Revolving credit facility Q3 and Q4 2012	Mar. 31, 2013 Revolving credit facility Q1 and Q2 2013	Mar. 31, 2013 Revolving credit facility Q3 2013 and thereafter	Mar. 31, 2013 Revolving credit facility Q3 2012 thru Q1 2013	Mar. 31, 2013 Revolving credit facility Q2 2013 thru Q4 2013	Mar. 31, 2013 Revolving credit facility Q1 2014 thru Q3 2014	Mar. 31, 2013 Revolving credit facility Q4 2014 and thereafter	Mar. 31, 2013 Letters of credit outstanding	Dec. 31, 2012 Letters of credit outstanding	Aug. 03, 2012 Letters of credit outstanding	Aug. 02, 2012 Letters of credit outstanding
Amended Credit Agreement
Maximum borrowing capacity																					$ 150	$ 50
Percentage of consolidated net worth that is factored into consolidated net worth covenant				85.00%
Maximum goodwill and intangible assets impairment charge added back to covenants		450.0
Percentage of net income for each fiscal quarter (with no deduction for net losses) factored into consolidated net worth covenant		50.00%
Percentage of aggregate amount of all equity issuances that increase stockholder's equity factored into consolidated net worth covenant		100.00%
Minimum fixed charge ratio												1.00	1.10	1.25
Maximum consolidated leverage ratio															4.25	3.75	3.25	2.75
Reference rate							British Bankers Association LIBOR rate			Federal Funds Rate	Bank of America prime rate
Basis points added to reference rate (as a percent)								2.00%	4.00%	0.50%	3.00%
Facility fees (as a percent)					0.375%	0.70%
Period of term loan	5 years
Loan outstanding	143.8
Outstanding borrowings		204.0	120.0
Letters of credit outstanding																			0.2	0.2
Available borrowing capacity		$ 95.8