Valuation and Qualifying Accounts (Tables)

6 Months Ended

Jun. 30, 2011

Valuation and Qualifying Accounts (Tables) [Abstract]

Valuation and Qualifying Accounts

	Balance at							Balance at
	Beginning of		Charged to					End of
	Period		Expense		Deductions(1)			Period
Allowance for doubtful accounts receivable:
Six months ended June 30, 2011	$	14,961		14,586		(11,444	)	$	18,103
Six months ended June 30, 2010	$	7,553		10,273		(6,644	)	$	11,182

(1) Deductions represent accounts written off, net of recoveries.