Restatement (Details Textuals) (USD $) In Millions, unless otherwise specified	Mar. 01, 2008	Feb. 29, 2004
Restatement (Textuals) [Abstract]
The amount of understatement of net income, total assets and total shareholders' equity		$ 14.8
Increase in deferred tax asset and retained earnings	$ 14.8

Understatement of net income assets and shareholders equity due to deferred tax asset.

No definition available.

Name:	am_UnderstatementOfNetIncomeAssetsAndShareholdersEquityDueToDeferredTaxAsset
Namespace Prefix:	am_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant