Impairments of Long-lived Assets - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended
Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Asset Impairment Charges [Abstract]
Impairment charges		$ 0us-gaap_AssetImpairmentCharges	$ 5,080,000us-gaap_AssetImpairmentCharges	$ 2,551,000us-gaap_AssetImpairmentCharges
Ceased covered airport parking lease term	7 years
Remaining lease period of released land lease	28 years
Future land lease payment ceased	$ 4,200,000

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2420-110228

Name:	us-gaap_AssetImpairmentCharges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration