Assets (Details 5) (USD $) In Thousands, unless otherwise specified	12 Months Ended							3 Months Ended		12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2012	Dec. 31, 2010	Sep. 30, 2012 (Level 1)	Sep. 30, 2012 (Level 2)	Sep. 30, 2012 (Level 3)	Dec. 31, 2011 Goodwill	Sep. 30, 2011 Goodwill	Dec. 31, 2012 Income approach Goodwill	Dec. 31, 2011 Income approach Goodwill	Dec. 31, 2011 Market approach Goodwill Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill impairment	$ 0	$ 132,376						$ 92,400	$ 40,000
Goodwill	0	0		131,299
Period to estimate cash flows										5 years	5 years
Long-term growth rate											3.00%
Discount rate											16.20%
Number of publicly traded companies used to estimate goodwill impairment												6
Control premium												13.00%
Reporting unit's fair value					0	0	296,543
Goodwill impairment charge			$ 132,376