Cost of Contracts, net Cost of Contracts, net - Summary of Cost of Contracts (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Other Deferred Costs, Net [Abstract]
Cost of contracts	$ 30.5	$ 30.4
Accumulated amortization	(21.6)	(19.0)
Cost of contracts, net	$ 8.9	$ 11.4

Accumulated amortization of other deferred costs capitalized at the end of the reporting period. Does not include deferred finance costs, deferred acquisition costs of insurance companies, or deferred leasing costs for real estate operations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Gross amount of other deferred costs capitalized at the end of the reporting period. Does not include deferred finance costs or deferred acquisition costs of insurance companies.

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Net amount of other deferred costs capitalized at the end of the reporting period. Does not include deferred finance costs or deferred acquisition costs of insurance companies.

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