Long-term debt: (Tables)

3 Months Ended

Mar. 31, 2013

Long-term debt:

Schedule of debt and equity components for the Convertible Notes

The debt and equity components for the Convertible Notes were as follows (in thousands):

	March 31,			December 31,
	2013			2012
Principal amount	$	91,978		$	91,978
Unamortized discount	(7,947		)	(9,494		)
Net carrying amount	84,031			82,484
Additional paid-in capital	74,933			74,933

Schedule of interest expense recognized and the effective interest rate for the Convertible Notes

At March 31, 2013, the unamortized discount had a remaining recognition period of approximately one year.  The amount of interest expense recognized and effective interest rate were as follows (in thousands):

	Three Months Ended March 31,
	2013			2012
Contractual coupon interest	$	230		$	230
Amortization of discount and costs on Notes	1,551			1,424
Interest expense	$	1,781		$	1,654
Effective interest rate	8.7		%	8.7		%