EMPLOYEE BENEFIT PLANS: (Tables)

12 Months Ended

Dec. 31, 2012

EMPLOYEE BENEFIT PLANS:

Schedule of amounts recognized in accumulated other comprehensive loss (pre-tax)

Prior service credit	$	(501	)
Net actuarial loss	6,574
Net amount recognized in accumulated other comprehensive loss	$	6,073

Schedule of changes in accumulated postretirement benefit obligation

	December 31
	2012			2011
Benefit obligation, beginning of year	$	26,108		$	20,689
Service cost	1,034			831
Interest cost	1,113			1,117
Actuarial (gain)/loss	(520		)	3,898
Benefits paid	(354		)	(427		)
Benefit obligation, end of year	$	27,381		$	26,108

Schedule of net periodic postretirement benefit cost

	2012		2011		2010
Service cost—benefits attributed to service during the period	$	1,034	$	831	$	696
Interest cost on the accumulated postretirement benefit obligation	1,113		1,117		958
Net amortization	1,036		501		128
Net periodic postretirement benefit cost	$	3,183	$	2,449	$	1,782

Schedule of increasing or decreasing health care trend rates by one percentage point

	1% Increase		1% Decrease
Postretirement benefit obligation	$	6,569	$	(4,281	)
Total of service and interest cost components	$	604	$	(407	)