Retirement Plan (Changes in Benefit Obligation and Plan Assets) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2012 Retirement Plan [Member]	Dec. 31, 2013 Retirement Plan [Member]	Dec. 31, 2012 Retirement Plan [Member]	Dec. 31, 2013 Post-retirement Healthcare Plans [Member]	Dec. 31, 2012 Post-retirement Healthcare Plans [Member]	Dec. 31, 2011 Post-retirement Healthcare Plans [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Pension plan's benefit obligation - beginning of year	$ 93,378	$ 95,485	$ 93,378	$ 26,797	$ 77,303
Service cost		0	679	1,112	1,892	1,569
Interest cost		1,797	3,962	665	3,519	2,193
Benefits paid		(3,957)	(1,379)	(1,585)	(1,275)
Amendments				(820)	(49,399)
Actuarial loss		2,981	13,203	(2,391)	(6,003)
Settlements paid	(7,256)	(96,306)	(7,256)	8,627	0
Curtailment	(7,102)	0
Pension plan's benefit obligation - end of year		0	95,485	15,715	26,797	77,303
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets - beginning of year	61,398	77,757	61,398	0	0
Actual return on plan assets		(219)	2,615
Participant contributions				564	760
Benefits paid		(3,957)	(1,379)	(1,585)	(1,275)
Employer contributions		22,725	22,379	9,648	515
Settlements				(8,627)	0
Settlements paid	(7,256)	(96,306)	(7,256)	8,627	0
Fair value of plan assets - end of year		0	77,757	0	0	0
Under-funded balance		0	(17,728)	(15,715)	(26,797)
Accrued liability		0	(17,728)	(15,715)	(26,797)
Cumulative actuarial loss		0	(37,589)	(1,022)	(5,359)
Prior service cost				47,098	52,174
Total				$ 46,076	$ 46,815