CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 4,966	$ 5,990	$ (330,308)
Other comprehensive income (loss), net of tax:
Net unrealized losses on available-for-sale investments	(2,125)	0	0
Defined benefit pension items:
Prior service cost arising during the period	0	0	(1,597)
Net gain (loss) arising during the period	2,191	(2,485)	(3,558)
Amortization and settlement included in net periodic cost	1,069	1,210	2,274
Amortization of prior service cost included in net periodic cost	0	2,503	1,106
Amortization and settlement related to post retirement medical plan included in net periodic cost	0	0	2,441
Total other comprehensive income (loss), net of tax	1,135	1,228	666
Total comprehensive income (loss)	$ 6,101	$ 7,218	$ (329,642)