Acquisitions (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended		0 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Jun. 10, 2014 Apollo Group Limited [Member]	Jun. 10, 2014 Apollo Group Limited [Member]
Business Acquisition [Line Items]
Contingent consideration, based on achievement of certain EBITDA targets				$ 2.4
Contingent consideration, measurement period for EBITDA targets			2 years
Contingent consideration, fair value at date of acquisition				1.1
Purchase consideration	$ 5.4	$ 21.6	$ 6.5