Description of Business and Summary of Significant Accounting Policies (Accounts Receivables and Allowances) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Document Period End Date			Sep. 30, 2016
Accounts receivable	$ 60,795		$ 60,795		$ 47,171
Allowance for doubtful accounts	1,909		1,909		$ 3,388
Deferred revenue included in accounts receivables	5,100		5,100
Provision for doubtful accounts	243	$ 1,650	700	$ 1,950
Allowance for Doubtful Accounts Receivable, Write-offs			2,200
Billed Revenues [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	49,900		49,900
Unbilled Revenues [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 12,800		$ 12,800
Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Delivery term for contractual elements of revenue arrangements			18 months