Cost of Contracts, net (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cost of Contracts, net
Cost of contracts	$ 25,607	$ 26,599
Accumulated amortization	(14,845)	(12,384)
Cost of contracts, net	10,762	14,215
Expected future amortization of cost of contracts
2014	2,355
2015	1,967
2016	1,789
2017	1,677
2018	1,437
2019 and Thereafter	1,537
Cost of contracts, net	10,762	14,215
Amortization expense, cost of contracts	2,788	3,142	2,275
Additional amortization expense recorded relating to losses of contracts	$ 0	$ 0	$ 0
Weighted average useful life	9 years 7 months 6 days	9 years 5 months	9 years 8 months 12 days

Amount of additional amortization expense of other deferred costs charged against earnings in the period.

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- Definition

Represents the amount of amortization expense expected to be recognized after the fifth fiscal year following the latest fiscal year for other deferred costs.

+ References

No definition available.

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Represents the amount of amortization expense expected to be recognized during the next fiscal year following the latest fiscal year for other deferred costs.

+ References

No definition available.

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Represents the amount of amortization expense expected to be recognized during the fifth fiscal year following the latest fiscal year for other deferred costs.

+ References

No definition available.

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Represents the amount of amortization expense expected to be recognized during the fourth fiscal year following the latest fiscal year for other deferred costs.

+ References

No definition available.

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Represents the amount of amortization expense expected to be recognized during the third fiscal year following the latest fiscal year for other deferred costs.

+ References

No definition available.

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Represents the amount of amortization expense expected to be recognized during the second fiscal year following the latest fiscal year for other deferred costs.

+ References

No definition available.

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Useful life of other deferred costs, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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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.

+ References

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

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 17

-Article 5

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Amount of amortization of other deferred costs recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.3)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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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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