Description of Business and Summary of Significant Accounting Policies (Accounts Receivables and Allowances) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Document Period End Date	Mar. 31, 2016
Accounts receivable	$ 56,503		$ 47,171
Allowance for doubtful accounts	1,046		$ 3,388
Deferred revenue included in accounts receivables	8,900
Provision for doubtful accounts	(241)	$ 9
Allowance for Doubtful Accounts Receivable, Write-offs	2,100
Billed Revenues [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	42,900
Unbilled Revenues [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 13,600
Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Delivery term for contractual elements of revenue arrangements	18 months