Significant Classes of Amortizable Intangible Assets by Major Category (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Cost	$ 35,332	$ 33,874
Accumulated Amortization	(27,196)	(25,121)
Net	8,136	8,753
Customer lists and contracts
Finite-Lived Intangible Assets [Line Items]
Cost	17,554	17,213
Accumulated Amortization	(13,834)	(12,665)
Net	3,720	4,548
Domain and brand names
Finite-Lived Intangible Assets [Line Items]
Cost	11,423	11,015
Accumulated Amortization	(7,864)	(7,192)
Net	3,559	3,823
Favorable and assigned leases
Finite-Lived Intangible Assets [Line Items]
Cost	2,358	1,649
Accumulated Amortization	(1,676)	(1,594)
Net	682	55
Other amortizable intangible assets
Finite-Lived Intangible Assets [Line Items]
Cost	3,997	3,997
Accumulated Amortization	(3,822)	(3,670)
Net	$ 175	$ 327