Description of Business and Summary of Significant Accounting Policies (Accounts Receivables and Allowances) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 38,361,000		$ 38,361,000		$ 39,070,000
Allowance for doubtful accounts	1,609,000		1,609,000		1,049,000
Deferred revenue included in accounts receivables	7,500,000		7,500,000
Provision for doubtful accounts	336,000	834,000	1,083,000	1,361,000
Billed Revenues [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	29,400,000		29,400,000
Unbilled Revenues [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 10,600,000		$ 10,600,000
Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Delivery term for contractual elements of revenue arrangements			18 months