Retirement Plans (Changes in Accumulated Other Comprehensive Income (Loss) Related to Retirement Plans) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss) at beginning of year	$ (35,393)	$ (28,665)
Prior service credits	83
Net actuarial gain (loss)	17,599
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Plan Amendments, Tax Effect	(329)
Change in adjustment for pension and other postretirement benefits, net of tax benefit (expense) of $(9,344), $3,623 and $6,051 for the years ended December 31, 2013, 2012 and 2011, respectively	17,353	(6,728)	(11,237)
Accumulated other comprehensive income (loss) at end of year	(18,040)	(35,393)	(28,665)
Pension Plan [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss) at beginning of year	(35,288)
Prior service credits	(1)
Net actuarial gain (loss)	17,310
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Plan Amendments, Tax Effect	0
Change in adjustment for pension and other postretirement benefits, net of tax benefit (expense) of $(9,344), $3,623 and $6,051 for the years ended December 31, 2013, 2012 and 2011, respectively	17,309
Accumulated other comprehensive income (loss) at end of year	(17,979)
Postretirement Plan [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss) at beginning of year	283
Prior service credits	84
Net actuarial gain (loss)	231
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Plan Amendments, Tax Effect	(329)
Change in adjustment for pension and other postretirement benefits, net of tax benefit (expense) of $(9,344), $3,623 and $6,051 for the years ended December 31, 2013, 2012 and 2011, respectively	(14)
Accumulated other comprehensive income (loss) at end of year	269
Supplemental Plan [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss) at beginning of year	(388)
Prior service credits	0
Net actuarial gain (loss)	58
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Plan Amendments, Tax Effect	0
Change in adjustment for pension and other postretirement benefits, net of tax benefit (expense) of $(9,344), $3,623 and $6,051 for the years ended December 31, 2013, 2012 and 2011, respectively	58
Accumulated other comprehensive income (loss) at end of year	$ (330)