Condensed Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Net Income	$ 5,134	$ 4,356	$ 22,815	$ 19,225
Employee Benefits, net of tax:
Amortization of prior service cost, net of tax of ($6), ($6), ($12), and ($12) respectively	9	9	18	18
Net gain, net of tax of $27, $43, $53 and $81, respectively	40	64	79	122
Commodity Contract Cash Flow Hedges [Abstract]
Unrealized loss on commodity contract cash flow hedges, net of tax of ($1), $0, ($1) and $0, respectively.	(1)		(1)
Total other comprehensive income	30	55	60	104
Comprehensive Income	$ 5,164	$ 4,411	$ 22,875	$ 19,329