Description of Business and Summary of Significant Accounting Policies (Accounts Receivables and Allowances) (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 42,210,000		$ 39,070,000
Deferred revenue included in accounts receivables	8,600,000
Provision for Doubtful Accounts	353,000	0
Billed Revenues [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	32,500,000
Unbilled Revenues [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 9,700,000
Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Delivery term for contractual elements of revenue arrangements	18 months