OTHER COMPREHENSIVE INCOME (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Unrealized gains on available-for- sale securities, before tax amount [Abstract]
Unrealized gains (losses) arising during holding period, before tax amount	$ 3,043	$ 55,882	$ (8,854)
Reclassification adjustment for net (gains) realized in net income, before tax amount	(442)	(12,127)	470
Change in pension funding status before tax amount	(12,930)	(23,963)	(1,423)
Other comprehensive income (loss), before tax amount	(10,329)	19,792	(9,807)
Unrealized gains on available-for- sale securities, tax (expense) benefit [Abstract]
Unrealized gains (losses) arising during holding period, tax (expense) benefit	(1,171)	(21,405)	3,399
Reclassification adjustment for net (gains) losses realized in net income, tax (expense) benefit	169	4,639	(180)
Change in pension funding status cost, tax (expense) benefit	4,946	9,166	544
Other comprehensive (loss) income, tax (expense) benefit	3,944	(7,600)	3,763
Unrealized gains on available-for- sale securities, net of tax amount [Abstract]
Unrealized gains (losses) arising during holding period, net of tax amount	1,872	34,477	(5,455)
Reclassification adjustment for net (gains) losses realized in net income, net of tax amount	(273)	(7,488)	290
Change in pension funding status cost, net of tax amount	(7,984)	(14,797)	(879)
Other comprehensive income	$ (6,385)	$ 12,192	$ (6,044)