Significant Accounting Policies - Concentration of Credit Risk (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 Financial_Institution	Dec. 31, 2013	Dec. 31, 2012
Concentration Risk [Line Items]
Number of financial institutions	1
Impairment of Long-Lived Assets to be Disposed of	$ 0.6	$ 0	$ 0
Sales Revenue, Net
Concentration Risk [Line Items]
Concentration risk (less than 1%)	10.00%
Number of individual foreign countries	0	0	0
Customer Concentration	0	0	0
Accounts Receivable
Concentration Risk [Line Items]
Concentration risk (less than 1%)	10.00%
Number of individual foreign countries	0	0
Customer Concentration	0
Fixed Assets
Concentration Risk [Line Items]
Concentration risk (less than 1%)	10.00%
Number of individual foreign countries	0