Employee Benefit Plans Pension Plan Assets Fair Value Measurement Reconciliation of Unobservable Inputs (Details) (Significant Unobservable Inputs (Level 3), USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Significant Unobservable Inputs (Level 3)
Change in plan assets:
Balance as of January 1	$ 9,031	$ 23,712
Transfers	(641)	(13,153)
Distributions	(1,018)	(2,669)
Contributions	0	0
Unrealized gain (loss) on long-term investments	3,403	(1,779)
Realized (loss) gain on long-term investments	(3,951)	2,920
Balance as of December 31	$ 6,824	$ 9,031