Benefit Plans (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended		3 Months Ended		6 Months Ended			3 Months Ended		6 Months Ended		18 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 Pension Benefits [Member]	Jun. 30, 2013 Pension Benefits [Member]	Jun. 30, 2014 Pension Benefits [Member]	Jun. 30, 2013 Pension Benefits [Member]		Jun. 30, 2014 Other Benefits [Member]	Jun. 30, 2013 Other Benefits [Member]	Jun. 30, 2014 Other Benefits [Member]	Jun. 30, 2013 Other Benefits [Member]	Dec. 31, 2015 Minimum [Member] Scenario, Forecast [Member]	Dec. 31, 2015 Maximum [Member] Scenario, Forecast [Member]
Components of net periodic benefit cost
Service cost			$ 732	$ 3,330	$ 1,464	$ 6,661		$ 0	$ 0	$ 0	$ 0
Interest cost			5,750	6,956	11,500	13,913		157	157	314	314
Expected return on plan assets			(6,449)	(8,802)	(12,898)	(17,605)		0	0	0	0
Amortization of prior service (benefit) cost			(39)	19	(78)	37		(56)	(122)	(113)	(244)
Recognized net actuarial loss			756	5,435	1,512	10,856		50	105	101	211
Curtailment loss					0	1,159	[1]			0	0
Net periodic pension benefit cost			750	6,938	1,500	15,021		151	140	302	281
Contributions to qualified and non qualified pension plans	2,813	1,597
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year												$ 5,000	$ 7,500

[1] Curtailment loss during the six months ended June 30, 2013 resulted from the departure of certain executive officers and was recorded within selling and administrative expense in the condensed consolidated statement of operations.