Fair Value of Financial Instruments and Concentrations of Credit Risk (Tables)

12 Months Ended

Dec. 31, 2011

Fair Value Disclosures [Abstract]

Summary of Accounts Receivable

	2011			2010
	(In thousands)
Gross trade receivables	$	306,791		$	193,349
Allowance for doubtful accounts		(3,161	)		(5,839	)
Net trade receivables		303,630			187,510
Other receivables		24,960			9,289
Total receivables, net	$	328,590		$	196,799

Summary of Allowance for losses on Accounts Receivables

	2011			2010			2009
	(In thousands)
Balance at beginning of year	$	5,839		$	5,969		$	4,259
Provision for uncollectible accounts		2,400			478			2,301
Write-offs, net of recoveries		(5,078	)		(608	)		(591	)
Balance at end of year	$	3,161		$	5,839		$	5,969