Business Combinations (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013
PointBridge [Member]
Business Acquisition [Line Items]
Date of acquisition	Feb. 08, 2012
Cash paid for acquisition	$ 14.4
Common stock issued	6.1
Transaction costs	0.7
PointBridge [Member] | Minimum [Member]
Business Acquisition [Line Items]
Intangible assets estimated useful life	11 months
PointBridge [Member] | Maximum [Member]
Business Acquisition [Line Items]
Intangible assets estimated useful life	5 years
Nascent [Member]
Business Acquisition [Line Items]
Date of acquisition	Jun. 01, 2012
Cash paid for acquisition	11.6
Common stock issued	5.2
Transaction costs	0.6
Nascent [Member] | Minimum [Member]
Business Acquisition [Line Items]
Intangible assets estimated useful life	7 months
Nascent [Member] | Maximum [Member]
Business Acquisition [Line Items]
Intangible assets estimated useful life	5 years
Northridge [Member]
Business Acquisition [Line Items]
Date of acquisition	Jul. 01, 2012
Cash paid for acquisition	10.7
Common stock issued	3.2
Transaction costs	0.6
Northridge [Member] | Minimum [Member]
Business Acquisition [Line Items]
Intangible assets estimated useful life	9 months
Northridge [Member] | Maximum [Member]
Business Acquisition [Line Items]
Intangible assets estimated useful life	5 years
TriTek [Member]
Business Acquisition [Line Items]
Date of acquisition	May 01, 2013
Cash paid for acquisition	17.0
Common stock issued	4.1
Transaction costs	0.8
TriTek [Member] | Minimum [Member]
Business Acquisition [Line Items]
Intangible assets estimated useful life	8 months
TriTek [Member] | Maximum [Member]
Business Acquisition [Line Items]
Intangible assets estimated useful life	8 years
ClearTask [Member]
Business Acquisition [Line Items]
Date of acquisition	May 17, 2013
Cash paid for acquisition	5.8
Common stock issued	1.3
Fair value estimate of additional earnings-based contingent consideration	1.4
Transaction costs	$ 0.6
ClearTask [Member] | Minimum [Member]
Business Acquisition [Line Items]
Intangible assets estimated useful life	5 months
ClearTask [Member] | Maximum [Member]
Business Acquisition [Line Items]
Intangible assets estimated useful life	5 years