(Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Goodwill and Intangible Assets (Additional Textual) [Abstract]
Goodwill impairment	$ 0	$ 0	$ 0
Amortization expense for intangible assets	$ 3,000,000	$ 1,700,000	$ 700,000
Customer relationships | Minimum
Goodwill and Intangible Assets (Additional Textual) [Abstract]
Period of amortization of intangible assets	5 years
Customer relationships | Maximum
Goodwill and Intangible Assets (Additional Textual) [Abstract]
Period of amortization of intangible assets	10 years