Intangible Assets (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Intangible Assets [Abstract]
Amortization expense for acquired intangible assets	$ 2.2	$ 2.3	$ 4.3	$ 4.6