EMPLOYEE BENEFIT PLANS: (Tables)

12 Months Ended

Dec. 31, 2013

EMPLOYEE BENEFIT PLANS:

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

Prior service credit	$	(10,801	)
Net actuarial loss	(3,956		)
Net amount recognized in accumulated other comprehensive (gain) loss	$	(14,757	)

Schedule of changes in accumulated postretirement benefit obligation

	December 31
	2013			2012
Benefit obligation, beginning of year	$	27,381		$	26,108
Service cost	1,036			1,034
Interest cost	1,060			1,113
Plan amendments	(10,425		)	—
Actuarial (gain)/loss	(9,734		)	(520		)
Benefits paid	(142		)	(354		)
Benefit obligation, end of year	$	9,176		$	27,381

Schedule of net periodic postretirement benefit cost

	2013		2012		2011
Service cost—benefits attributed to service during the period	$	1,036	$	1,034	$	831
Interest cost on the accumulated postretirement benefit obligation	1,060		1,113		1,117
Net amortization	671		1,036		501
Net periodic postretirement benefit cost	$	2,767	$	3,183	$	2,449