PROPERTY AND EQUIPMENT, NET (PropertyAnd Equipment) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 263,179	$ 238,772
Less accumulated depreciation and amortization	(157,455)	(134,159)
Property and equipment, net	105,724	104,613	103,449
Operations equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	92,560	86,742
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	10,829	8,701
Office equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	4,280	4,062
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	31,684	32,762
Capitalized software
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	109,891	94,453
Construction in progress
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	12,759	10,426
Building
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 1,176	$ 1,626