INCOME TAXES AND RELATED PAYMENTS - Reconciliation of Unrecognized Tax Benefits (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of period	$ 9,472	$ 8,594	$ 7,955
Additions for tax positions related to the current year	1,633	72	822
Additions for tax positions related to prior years	1,029	806	0
Reductions for tax positions related to prior years	(806)	0	0
Settlement of tax positions	0	0	0
Lapse of statute of limitations	(938)	0	(183)
Balance at end of period	$ 10,390	$ 9,472	$ 8,594