PROPERTY AND EQUIPMENT, NET (PropertyAnd Equipment) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 238,772	$ 212,221
Less accumulated depreciation and amortization	(134,159)	(108,772)
Property and equipment, net	104,613	103,449	107,238
Operations Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	86,742	76,678
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	8,701	8,370
Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	4,062	2,471
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	32,762	31,746
Software [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	94,453	79,592
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	10,426	11,808
Building [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 1,626	$ 1,556