Components of Net Periodic Benefit Cost (Tables)

9 Months Ended

Sep. 30, 2015

Compensation and Retirement Disclosure [Abstract]

Schedule of Net Benefit Costs

	Three Months Ended September 30,										Nine Months Ended September 30,
	(000's)										(000's)
	Pension Benefits						Post-Retirement Health Benefits				Pension Benefits						Post-Retirement Health Benefits
	2015			2014			2015		2014		2015			2014			2015		2014
Service cost	$	538		$	510		$	16	$	13	$	1,615		$	1,530		$	47	$	40
Interest cost	879			939			43		44		2,637			2,817			130		131
Expected return on plan assets	(863		)	(948		)	—		—		(2,589		)	(2,845		)	—		—
Amortization of transition obligation	—			—			—		—		—			—			—		—
Net amortization of prior service cost	—			(2		)	—		—		1			(7		)	—		—
Net amortization of net (gain) loss	1,185			190			—		—		3,555			569			—		(1		)
Net Periodic Benefit Cost	$	1,739		$	689		$	59	$	57	$	5,219		$	2,064		$	177	$	170