ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS): (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Accumulated other comprehensive income (loss)
Balance at the beginning of the period	$ 2,794	$ (1,164)
Other comprehensive income/loss before reclassifications	4,629	3,069
Amounts reclassified from accumulated other comprehensive income/loss	(6,033)	889
Net current-period other comprehensive income/loss, net of taxes	(1,404)	3,958
Balance at the end of the period	1,390	2,794
Unrealized Gains / Losses on Available-for-Sale Securities
Accumulated other comprehensive income (loss)
Balance at the beginning of the period	(148)	(15)
Other comprehensive income/loss before reclassifications	148	(129)
Amounts reclassified from accumulated other comprehensive income/loss	(6)	(4)
Net current-period other comprehensive income/loss, net of taxes	142	(133)
Balance at the end of the period	(6)	(148)
Gains / Losses on Derivatives
Accumulated other comprehensive income (loss)
Balance at the beginning of the period	2,942	(1,149)
Other comprehensive income/loss before reclassifications	4,481	3,198
Amounts reclassified from accumulated other comprehensive income/loss	(6,027)	893
Net current-period other comprehensive income/loss, net of taxes	(1,546)	4,091
Balance at the end of the period	$ 1,396	$ 2,942