Summary of Significant Accounting Policies - Property, Equipment and Capitalized Software Costs (Details)	12 Months Ended
	Dec. 31, 2014
Minimum
Property, Equipment and Capitalized Software [Line Items]
Property, equipment and capitalized software, useful life	1 year
Maximum
Property, Equipment and Capitalized Software [Line Items]
Property, equipment and capitalized software, useful life	30 years
Software Development [Member] | Minimum
Property, Equipment and Capitalized Software [Line Items]
Property, equipment and capitalized software, useful life	2 years
Software Development [Member] | Maximum
Property, Equipment and Capitalized Software [Line Items]
Property, equipment and capitalized software, useful life	5 years