Exhibit 12

Computation of Ratios of Earnings to Fixed Costs

																			Pro Forma
																Nine Months Ended September 30, 2011			Year Ended December 31, 2010			Nine Months Ended September 30, 2011
	Year Ended December 31,
	2010			2009			2008			2007			2006
	(Dollars in thousands, except ratios)
Earnings:
Income before income taxes	$	193,248		$	231,968		$	171,063		$	36,832		$	75,100		$	61,473		$	131,143		$	34,149
Fixed charges		6,973			6,976			12,076			17,634			8,354			14,035			47,688			36,223
Amortization of capitalized interest		558			472			235			237			241			425			558			425
Less:
Capitalized interest		(701	)		(1,493	)		(3,999	)		(4,280	)		—			(5,344	)		(7,777	)		(16,277	)
Noncontrolling interest in pre-tax income of subsidiaries that have not incurred fixed charges		(7,107	)		(21,552	)		(19,028	)		(19,883	)		(37,864	)		1,226			(7,107	)		1,226
Adjusted earnings	$	192,971		$	216,371		$	160,347		$	30,540		$	45,831		$	71,816		$	164,505		$	55,747
Fixed Charges:
Interest cost—affiliate	$	5,435		$	5,663		$	11,187		$	16,569		$	7,706		$	3,565		$	—		$	—
Interest cost		—			—			—			—			—			8,860			46,150			34,613
Interest portion of rent expense*		1,538			1,313			889			1,065			648			1,610			1,538			1,610
Total fixed charges	$	6,973		$	6,976		$	12,076		$	17,634		$	8,354		$	14,035		$	47,688		$	36,223
Ratios of earnings to fixed charges		27.7			31.0			13.3			1.7			5.5			5.1			3.4			1.5

* Represents one-third of the total operating lease rental expense which is that portion deemed to be interest