Accumulated Other Comprehensive Income Changes in AOCI (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	$ (10,840)
Other comprehensive income (loss) before reclassifications	6,543
Amounts reclassified from accumulated other comprehensive loss	1,681
Net other comprehensive income (loss) for the year	8,224	(1,770)	(2,037)
Accumulated other comprehensive income (loss), ending balance	(2,616)	(10,840)
Benefits Liability, Net of Tax
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	(16,351)
Other comprehensive income (loss) before reclassifications	7,986
Amounts reclassified from accumulated other comprehensive loss	1,669
Net other comprehensive income (loss) for the year	9,655
Accumulated other comprehensive income (loss), ending balance	(6,696)
Cumulative Foreign Currency Exchange
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	5,511
Other comprehensive income (loss) before reclassifications	(1,607)
Amounts reclassified from accumulated other comprehensive loss	0
Net other comprehensive income (loss) for the year	(1,607)
Accumulated other comprehensive income (loss), ending balance	3,904
Net Unrealized Holding Gains on Investments, Net of Tax
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	0
Other comprehensive income (loss) before reclassifications	164
Amounts reclassified from accumulated other comprehensive loss	12
Net other comprehensive income (loss) for the year	176
Accumulated other comprehensive income (loss), ending balance	$ 176