Fair Value Measurements (Details 2) (USD $)	3 Months Ended			12 Months Ended
	Dec. 31, 2011	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Fair value measurements
Equity investments	$ 0			$ 0
Total losses
Goodwill and other asset impairment	4,282,000	225,035,000	5,375,000	229,317,000	5,375,000
Equity investments				4,282,000
Total				229,317,000
Goodwill	274,292,000			274,292,000	468,479,000	425,301,000
U.S. Operations
Total losses
Goodwill and other asset impairment		225,035,000		225,035,000
Goodwill	245,105,000	470,100,000		245,105,000	439,294,000	390,721,000
Non-recurring basis | U.S. Operations | Total
Fair value measurements
Goodwill - U.S. Operations	245,118,000			245,118,000
Total	245,118,000			245,118,000
Non-recurring basis | U.S. Operations | Level 1
Fair value measurements
Goodwill - U.S. Operations	245,118,000			245,118,000
Total	$ 245,118,000			$ 245,118,000