COMMITMENTS AND CONTINGENCIES (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Leases
Rent expense incurred relating to operating leases	$ 2,756	$ 2,818	$ 8,051	$ 8,501
Future minimum rental payments
Remainder of 2014	3,536		3,536
2015	12,778		12,778
2016	12,266		12,266
2017	12,224		12,224
2018	12,915		12,915
Thereafter	23,096		23,096
Total	76,815		76,815
Unsecured revolving credit facility
Bank line of credit
Commitment amount	25,000		25,000
Fixed rate of interest (as a percent)	3.50%		3.50%
Borrowings under the credit facility	0	0	0	0
Available credit under the facility	16,669		16,669
Unsecured revolving credit facility | LIBOR
Bank line of credit
Reference rate (as a percent)			LIBOR
Interest rate margin (as a percent)			1.00%
Unsecured revolving credit facility | Prime
Bank line of credit
Reference rate (as a percent)			Prime
Interest rate margin (as a percent)			(1.50%)
Standby letters of credit
Bank line of credit
Letters of credit outstanding	$ 8,331		$ 8,331
Fee on the outstanding balances (as a percent)			1.00%