Description of Business and Summary of Significant Accounting Policies (Accounts Receivables and Allowances) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Net, Current	$ 41,100,000	$ 39,070,000
Allowance for doubtful accounts	1,619,000	1,049,000
Deferred revenue included in accounts receivables	5,800,000	6,700,000
Bad debt expense	1,600,000	1,147,000	442,000
Billed Revenues
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Net, Current	32,400,000	31,200,000
Unbilled Revenues
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Net, Current	$ 8,500,000	$ 7,900,000