Supplemental Cash Flow Information (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Supplemental non-cash investing and financing activities:
Fair value of warrant liability reclassified to additional paid-in capital	$ 13,973	$ 0	$ 0
Value of common stock issued in payment of convertible notes	0	5,165	0
Value of common stock issued in payment of preferred stock dividends		3,254
Value of common stock issued in payment of term loan debt		1,398
Equipment acquired through capital leases	1,263	1,334	615
Value of common stock issued in payment of debt issuance costs	0	0	5,096
Reduction in convertible debt upon note exchange	0	0	1,996
Value of common stock issued in exchange for convertible notes		0	1,992
Debt related commitment fees included in accrued liabilities	0	0	1,000
Exercise of stock options by common stock surrender	0	0	111
Supplemental cash payment information:
Interest paid	5,521	7,627	10,901
Income taxes paid (refunded)	14,049	(904)	(6,186)
Preferred Stock Dividends [Member]
Supplemental non-cash investing and financing activities:
Value of common stock issued in payment of preferred stock dividends	0	3,254	0
Term Loan Debt [Member]
Supplemental non-cash investing and financing activities:
Value of common stock issued in payment of term loan debt	0	1,398	0
Conversion of Preferred Stock [Member]
Supplemental non-cash investing and financing activities:
Value exchanged in conversion of preferred stock to common stock	$ 0	$ 11,205	$ 4,795