Fair Value Measurements (Fair Value Assets(Liabilities) Measured On Recurring Basis) (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonqualified savings plan assets	$ 11,576	$ 12,838	$ 14,826
Investment in equity securities	109,140	131,584
Total	120,716	144,422	14,826
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonqualified savings plan assets	11,090	12,259	14,826
Investment in equity securities	0	0
Total	11,090	12,259	14,826
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonqualified savings plan assets	486	579	0
Investment in equity securities	109,140	131,584
Total	109,626	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