Description of Business and Summary of Significant Accounting Policies (Accounts Receivables and Allowances) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 40,416,000		$ 40,416,000		$ 39,070,000
Allowance for doubtful accounts	1,450,000		1,450,000		1,049,000
Deferred revenue included in accounts receivables	8,000,000		8,000,000
Provision for Doubtful Accounts	395,000	527,000	748,000	527,000
Billed Revenues [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	32,300,000		32,300,000
Unbilled Revenues [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 9,600,000		$ 9,600,000
Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Delivery term for contractual elements of revenue arrangements			18 months