INTANGIBLE ASSETS (Tables)
 3 Months Ended
Mar. 31, 2015
Intangibles and Other Assets [Abstract]  
Schedule of acquired finite-lived intangible assets by major class
Intangible assets consist of the following (in thousands, except amortization period data):
 
March 31,
2015
 
December 31,
2014
 
Weighted-
Average
Amortization
Period (in years)
Capitalized product development cost
$
2,243

 
$
2,140

 
4
Accumulated amortization
(2,146
)
 
(2,140
)
 
 
Capitalized product development cost, net
97

 
—

 
 
 
 
 
 
 
 
Building photography
14,900

 
14,943

 
5
Accumulated amortization
(12,795
)
 
(12,665
)
 
 
Building photography, net
2,105

 
2,278

 
 
 
 
 
 
 
 
Acquired database technology
77,163

 
88,739

 
5
Accumulated amortization
(54,527
)
 
(60,498
)
 
 
Acquired database technology, net
22,636

 
28,241

 
 
 
 
 
 
 
 
Acquired customer base
199,230

 
199,826

 
10
Accumulated amortization
(109,030
)
 
(102,443
)
 
 
Acquired customer base, net
90,200

 
97,383

 
 
 
 
 
 
 
 
Acquired trade names and other intangible assets (1)
127,996

 
128,171

 
13
Accumulated amortization
(16,335
)
 
(14,451
)
 
 
Acquired trade names and other intangible assets, net
111,661

 
113,720

 
 
 
 
 
 
 
 
Intangible assets, net
$
226,699

 
$
241,622

 
 
 
(1) The weighted-average amortization period for acquired trade names excludes $48.7 million for acquired trade names recorded in connection with the LoopNet acquisition on April 30, 2012, which amount is not amortized, but is subject to annual impairment tests.