Accumulated Other Comprehensive Income (Loss) (Details) (USD $)	3 Months Ended												10 Months Ended		12 Months Ended
	Dec. 31, 2012		Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012		Dec. 31, 2011		Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011		Dec. 31, 2012		Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Accumulated Other Comprehensive Income (Loss) [Abstract]
Quantifying Misstatement in Current Year Financial Statements, Amount				$ 622,000
Comprehensive income															12,992,000		7,809,000		12,325,000
Net Income	2,525,000		1,741,000	1,738,000	2,294,000		1,574,000		2,133,000	2,348,000	2,346,000		939,000		8,298,000		8,401,000		12,592,000
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Unrecognized Net Actuarial Loss					(4,375,000)	[1]					(3,650,000)	[1]			(4,375,000)	[1]	(3,650,000)	[1]	(3,380,000)	[1]
Unrecognized Prior Service Credit					277,000	[1]					180,000	[1]			277,000	[1]	180,000	[1]	213,000	[1]
Unrecognized Transition Asset					(37,000)	[1]					(73,000)	[1]			(37,000)	[1]	(73,000)	[1]	(109,000)	[1]
Accumulated Other Comprehensive Income (Loss)					(4,135,000)						(3,543,000)				(4,135,000)		(3,543,000)		(3,276,000)
Net unamortized gain (loss) arising during period, net of tax															307,000	[1]	(725,000)	[1]	(270,000)	[1]
Net prior service costs (credit) arising during period, net of tax															4,350,000	[1]	97,000	[1]	(33,000)	[1]
Net transition asset (obligation) recognized in net periodic benefit cost, net of tax															37,000	[1]	36,000	[1]	36,000	[1]
Change in accumulated other comprehensive income															4,694,000		(592,000)		(267,000)
Unrecognized Net Actuarial Loss	(4,068,000)	[1]					(4,375,000)	[1]					(4,068,000)	[1]	(4,068,000)	[1]	(4,375,000)	[1]	(3,650,000)	[1]
Unrecognized Prior Service Credit	4,627,000	[1]					277,000	[1]					4,627,000	[1]	4,627,000	[1]	277,000	[1]	180,000	[1]
Unrecognized Transition Asset	0	[1]					(37,000)	[1]					0	[1]	0	[1]	(37,000)	[1]	(73,000)	[1]
Accumulated Other Comprehensive Income (Loss)	559,000						(4,135,000)						559,000		559,000		(4,135,000)		(3,543,000)
Income Tax Benefits of Accumulated Other Comprehensive Income Loss [Roll Forward]
Income tax related to OCI components beginning of year					2,736,000						2,344,000				2,736,000		2,344,000		2,168,000
Income tax (liability) changes related to [Abstract]
Unrecognized net actuarial loss															(203,000)		480,000		178,000
Unrecognized prior service credit															(2,879,000)		(64,000)		22,000
Unrecognized transition asset															(24,000)		(24,000)		(24,000)
Income tax related to OCI components end of year	$ (370,000)						$ 2,736,000						$ (370,000)		$ (370,000)		$ 2,736,000		$ 2,344,000

[1] Amounts pertain to our post-retirement benefit plans.