Pension and Other Postretirement Benefits (Details 10) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Defined benefit pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated future employer contributions in next fiscal year	$ 7,400
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2014	30,364
2015	29,231
2016	29,513
2017	29,737
2018	30,549
Years 2019-2023	152,050
Total	301,444
Other postretirement benefit plans [Member]
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2014	4,675
2015	4,287
2016	4,156
2017	4,276
2018	4,085
Years 2019-2023	17,319
Total	$ 38,798