Significant Accounting Policies (Details) (USD $)	12 Months Ended
	Dec. 31, 2014
Significant Of Accounting Policies [Line Items]
Senior Notes	120,000,000
Minimum [Member]
Significant Of Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	1 year
Maximum [Member]
Significant Of Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life	7 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	5 years
LP Units [Member]
Significant Of Accounting Policies [Line Items]
Limited Partnership Units Convertible Conversion Ratio	1