Acquisition (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
Summary of acquired intangible assets
Costs	13,255
Maximum [Member]
Summary of acquired intangible assets
Useful Lives	15 years
Minimum [Member]
Summary of acquired intangible assets
Useful Lives	3 years
Tradename - indefinite life [Member]
Summary of acquired intangible assets
Costs	1,820
Other [Member]
Summary of acquired intangible assets
Costs	300
Customer relationships [Member]
Summary of acquired intangible assets
Costs	5,455
Customer relationships [Member] | Maximum [Member]
Summary of acquired intangible assets
Useful Lives	15 years
Customer relationships [Member] | Minimum [Member]
Summary of acquired intangible assets
Useful Lives	10 years
Internally developed software [Member]
Summary of acquired intangible assets
Costs	5,000
Useful Lives	3 years
Tradename - finite life [Member]
Summary of acquired intangible assets
Costs	300
Useful Lives	3 years
Non-compete agreement [Member]
Summary of acquired intangible assets
Costs	380
Useful Lives	3 years