Property and Equipment, Net (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Property and Equipment, Net (Textual) [Abstract]
Depreciation and amortization expense	$ 2.5	$ 2.6	$ 7.1	$ 7.1
Total property and equipment assets under capital lease	3.2		3.2		3.3
Accumulated depreciation related to assets under capital lease	2.0		2.0		1.6
Internal-use software development costs	1.5	1.8	6.6	3.8
Capitalized costs related to internal-use software, net of accumulated amortization	11.3		11.3		9.2
Amortization of capitalized costs related to internal-use software	$ 0.8	$ 1.2	$ 2.1	$ 3.1

For each income statement presented, the amount charged to expense for amortization of capitalized computer software costs.

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The carrying amount of capitalized computer software costs net of accumulated amortization as of the balance sheet date.

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- Definition

The total charge for the use of long-lived depreciable assets subject to a lease meeting the criteria for capitalization.

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- Definition

The current period expense charged against earnings on long-lived, physical assets not used in production, and which are not intended for resale, to allocate or recognize the cost of such assets over their useful lives; or to record the reduction in book value of an intangible asset over the benefit period of such asset; or to reflect consumption during the period of an asset that is not used in production.

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