Exhibit 12

COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES

	Quarter Ended March 31, 2012			Years Ended December 31,
				2011			2010			2009			2008			2007
(In thousands)
Earnings from continuing operations before income taxes	$	77,570		$	258,524		$	185,340		$	140,390		$	418,199		$	249,997
Add:
Interest on indebtedness		7,020			33,873			36,545			35,347			47,011			33,311
Amortization of debt expense		262			1,033			1,037			973			1,070			796
Portion of rents representative of the interest factor		2,570			10,106			9,472			10,109			10,636			8,383
Deduct:
Undistributed earnings from less-than-50-percent-owned entities		—			(355	)		(352	)		(132	)		(66	)		427
Earnings (as defined)	$	87,422		$	303,181		$	232,042		$	186,687		$	476,850		$	292,914
Fixed charges:
Interest on indebtedness	$	7,020		$	33,873		$	36,545		$	35,347		$	47,011		$	33,311
Amortization of debt expense		262			1,033			1,037			973			1,070			796
Portion of rents representative of the interest factor		2,570			10,106			9,472			10,109			10,636			8,383
Total fixed charges	$	9,852		$	45,012		$	47,054		$	46,429		$	58,717		$	42,490
Ratio of earnings to fixed charges		8.9	x		6.7	x		4.9	x		4.0	x		8.1	x		6.9	x