Description of Business and Significant Accounting Policies (Details) (USD $)	3 Months Ended								12 Months Ended			36 Months Ended	3 Months Ended	12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012 Item	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011 Error attributable to the misapplication of U.S. GAAP	Sep. 30, 2012 Error attributable to the misapplication of U.S. GAAP Restatement adjustment	Dec. 31, 2012 Error attributable to the misapplication of U.S. GAAP Restatement adjustment
Accounting Review
Minimum number of multiple element arrangements examined									100
Accounting Review
Overstated cumulative net income												$ 600,000
Revenues	106,849,000	132,715,000	136,547,000	139,909,000	191,685,000	267,959,000	264,815,000	254,676,000	516,020,000	979,135,000	930,892,000			2,200,000
Income from continuing operations	(8,642,000)	7,698,000	11,011,000	16,462,000	23,588,000	52,617,000	56,318,000	57,979,000	26,529,000	190,502,000	277,176,000		500,000	(600,000)
Revenue retention percentage									10.00%
Accounts Receivable, Net
Allowance for doubtful accounts	$ 500,000				$ 500,000				$ 500,000	$ 500,000