Summary of Significant Accounting Policies (Goodwill) (Details) (USD $)
|
Sep. 30, 2012
|
Jun. 30, 2012
industry
|
Sep. 30, 2011
|
Jun. 30, 2011
|
Sep. 30, 2010
|
Sep. 30, 2009
|
---|---|---|---|---|---|---|
Goodwill [Line Items] | ||||||
Market capitalization | $ 263,300,000 | $ 264,300,000 | ||||
Carrying value | $ 270,857,000 | $ 265,700,000 | $ 260,716,000 | $ 240,556,000 | $ 229,586,000 | |
Control premium percent | 40.00% | 40.00% | ||||
Percent fair value in excess of carrying value of goodwill | 36.00% | 39.00% | 28.60% | |||
Number of industries encompasses similar products | 3 | |||||
Minimum [Member]
|
||||||
Goodwill [Line Items] | ||||||
Control premium percent | 30.00% | |||||
Target company's equity benchmark | 50.00% | |||||
Maximum [Member]
|
||||||
Goodwill [Line Items] | ||||||
Control premium percent | 45.00% |