Consolidated Statements of Comprehensive Income (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)	$ (22,055)	$ 30,445	$ 314,990
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments, net of tax benefit (expense) of $0 in 2013, $(27) in 2012 and $147 in 2011	3,325	3,902	(6,863)
Actuarial gains (losses) related to defined benefit pension plans, net of tax benefit (expense) of $(1,210) in 2013, $2,628 in 2012 and $0 in 2011	2,913	(6,778)	(197)
Unrealized holding gains (losses) on investments arising during period, net of tax benefit of $339 in 2013, $155 in 2012 and $0 in 2011	147	(946)	179
Reclassification adjustment for other-than-temporary impairment in value of investments, net of tax benefit of $450 in 2012	0	786	0
Other comprehensive income (loss)	6,385	(3,036)	(6,881)
Total comprehensive income (loss)	$ (15,670)	$ 27,409	$ 308,109