Internal Use Software Development Costs (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Research and Development [Abstract]
Capitalized computer software, additions	$ 9,400,000	$ 4,100,000	$ 3,900,000
Capitalized computer software, amortization	5,100,000	2,700,000	2,000,000
Internal use software development costs, write-offs	700,000	200,000
Estimated amortization expense, 2015	5,200,000
Estimated amortization expense, 2016	4,000,000
Estimated amortization expense, 2017	2,200,000
Estimated amortization expense, 2018	100,000
Capitalized computer software, impairments	$ 0	$ 0	$ 0