Property and equipment Useful Lives (Details)	12 Months Ended
	Dec. 31, 2013
Minimum [Member] | Computer And related software [Member]
Property Plant And Equipment Estimated Useful Lives [Line Items]
Property, Plant and Equipment, Useful Life	2 years
Minimum [Member] | Other Equipment [Member]
Property Plant And Equipment Estimated Useful Lives [Line Items]
Property, Plant and Equipment, Useful Life	2 years
Minimum [Member] | Furniture and Fixtures [Member]
Property Plant And Equipment Estimated Useful Lives [Line Items]
Property, Plant and Equipment, Useful Life	2 years
Maximum [Member] | Computer And related software [Member]
Property Plant And Equipment Estimated Useful Lives [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Maximum [Member] | Other Equipment [Member]
Property Plant And Equipment Estimated Useful Lives [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Maximum [Member] | Furniture and Fixtures [Member]
Property Plant And Equipment Estimated Useful Lives [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Maximum [Member] | Telecommunication Equipment [Member]
Property Plant And Equipment Estimated Useful Lives [Line Items]
Property, Plant and Equipment, Useful Life	10 years