Fair Value Measurements (Fair Value Assets(Liabilities) Measured On Recurring Basis) (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonqualified savings plan assets	$ 10,406	$ 12,838	$ 12,739
Investment in equity securities	66,354	131,584
Total	76,760	144,422	12,739
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonqualified savings plan assets	10,406	12,259	12,739
Investment in equity securities	66,354	0
Total	76,760	12,259	12,739
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonqualified savings plan assets	0	579	0
Investment in equity securities	0	131,584
Total	0	132,163	0
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonqualified savings plan assets	0	0	0
Investment in equity securities	0	0
Total	$ 0	$ 0	$ 0