Cash Convertible Senior Notes and Related Transactions (Tables)

6 Months Ended

Jun. 30, 2011

Cash Convertible Senior Notes and Related Transactions [Abstract]

Principal amount, carrying amount, and interest expense of the notes

	June 30,			December 31,
	2011			2010
Principal amount	$	175.0		$	175.0
Less: unamortized issuance discount		(30.4	)		(33.6	)
Carrying amount, net of discount	$	144.6		$	141.4

	Quarter Ended				Six Months Ended
	June 30,				June 30,
	2011		2010		2011		2010
Contractual coupon interest	$	1.9	$	1.9	$	3.9	$	2.0
Amortization of discount and deferred financing costs		1.9		1.8		3.8		1.8
Total interest expense1	$	3.8	$	3.7	$	7.7	$	3.8

¹ A portion of the interest relating to the Notes is capitalized as Construction in progress.