Description of Business and Summary of Significant Accounting Policies (Accounts Receivables and Allowances) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Document Period End Date			Jun. 30, 2015
Accounts receivable	$ 47,217		$ 47,217		$ 41,100
Allowance for doubtful accounts	1,449		1,449		$ 1,619
Deferred revenue included in accounts receivables	5,500		5,500
Provision for doubtful accounts	292	$ 395	301	$ 748
Allowance for Doubtful Accounts Receivable, Write-offs			470
Billed Revenues [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	37,100		37,100
Unbilled Revenues [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 10,100		$ 10,100
Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Delivery term for contractual elements of revenue arrangements			18 months