Intangible Assets - Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Contract intangibles	$ 82,972	$ 82,972
Other intangibles	3,004	3,004
Less accumulated amortization	(26,263)	(25,243)
Total intangible assets, net	$ 59,713us-gaap_FiniteLivedIntangibleAssetsNet	$ 60,733us-gaap_FiniteLivedIntangibleAssetsNet

Gross carrying amount before accumulated amortization as of the balance sheet date of an intangible asset that arises from a contractual arrangement with a third party (not including franchise rights and license agreements).

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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- Definition

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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- Definition

Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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- Definition

Gross carrying amount before accumulated amortization as of the balance sheet date of intangible assets not otherwise specified in the taxonomy having a reasonably expected period of economic benefit.

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