CAPITAL STOCK, Employee Stock Purchase Plan (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	4 Months Ended	12 Months Ended
	Apr. 30, 2008	Dec. 31, 2011 Employee Stock Purchase Plan [Member]	Dec. 31, 2010 Employee Stock Purchase Plan [Member]	Dec. 31, 2009 Employee Stock Purchase Plan [Member]
Employee Stock Purchase Plan [Abstract]
Employee purchase price, percent of market value	85.00%
Weighted-average assumptions and fair value of shares issued under the ESPP
Expected dividend yield (in hundredths)		0.00%	0.00%	0.00%
Risk-free interest rate (in hundredths)		0.24%	1.18%	1.40%
Expected volatility (in hundredths)		47.20%	45.10%	54.40%
Expected life (in years)		0.25	0.24	0.25
Weighted-average fair value of shares issued (in dollars per share)		$ 1.88	$ 2.14	$ 1.94
Shares issued under the ESPP (in shares)		124,219	107,748	129,949
Average price of shares issued (in dollars per share)		$ 9.71	$ 11.17	$ 9.70