Pension and Other Postretirement Benefits (Tables)

6 Months Ended

Jun. 30, 2014

Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]

Schedule of Net Benefit Costs [Table Text Block]

The net periodic benefit cost for the three and six months ended June 30, 2014 and 2013 included the following components: 

	Pension Benefits						Postretirement Benefits
	Three Months Ended   June 30,						Three Months Ended   June 30,
Components of Net Periodic Benefit Cost	2014			2013			2014			2013
Service cost	$	5,506		$	5,534		$	602		$	647
Interest cost	6,610			5,982			843			711
Expected return on plan assets	(6,637		)	(5,979		)	—			—
Amortization of:
Net actuarial loss	4,285			6,860			359			422
Prior service cost (gain)	230			338			(540		)	(540		)
Net periodic benefit cost	$	9,994		$	12,735		$	1,264		$	1,240
	Pension Benefits						Postretirement Benefits
	Six Months Ended   June 30,						Six Months Ended   June 30,
Components of Net Periodic Benefit Cost	2014			2013			2014			2013
Service cost	$	11,103		$	12,059		$	1,227		$	1,322
Interest cost	13,409			11,957			1,668			1,436
Expected return on plan assets	(13,312		)	(11,954		)	—			—
Amortization of:
Net actuarial loss	8,819			13,185			634			897
Prior service cost (gain)	476			688			(1,090		)	(1,090		)
Settlement loss	789			—			—			—
Net periodic benefit cost	$	21,284		$	25,935		$	2,439		$	2,565