Accounts Receivable

9 Months Ended

Sep. 30, 2011

Accounts Receivable [Abstract]

Accounts Receivable

(4)    Accounts Receivable:

The components of accounts receivable, net are as follows:

($ in thousands)	September 30, 2011			December 31, 2010
End user	$	559,411		$	627,573
Other		28,747			14,306
Less: Allowance for doubtful accounts		(60,763	)		(73,571	)
Accounts receivable, net	$	527,395		$	568,308

We maintain an allowance for estimated bad debts based on our estimate of our ability to collect accounts receivable. Bad debt expense, which is recorded as a reduction to revenue, was $19.3 million and $20.3 million for the three months ended September 30, 2011 and 2010, respectively, and $65.7 million and $31.6 million for the nine months ended September 30, 2011 and 2010, respectively.