Pension Plans and Other Postretirement Benefits (Details-3) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 315,000	$ 244,401
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,109	5,627
Equity Securities [Member] | U.S. Large Cap [Memeber]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	96,258	68,671
Equity Securities [Member] | U.S. Mid Cap [Memeber]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	22,741	16,741
Equity Securities [Member] | U.S. Small Cap [Memeber]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	28,854	21,222
Equity Securities [Member] | International Blend [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	54,873	44,200
Fixed Income Securities [Member] | Short-Term Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,789	4,231
Fixed Income Securities [Member] | High Yield Bond [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15,127	11,587
Fixed Income Securities [Member] | Long Duration Bond [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	66,193	53,515
Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	19,628	17,141
Insurance Continuance Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,428	1,466
Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,109	5,627
Level 1 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,109	5,627
Level 1 [Member] | Equity Securities [Member] | U.S. Large Cap [Memeber]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 1 [Member] | Equity Securities [Member] | U.S. Mid Cap [Memeber]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 1 [Member] | Equity Securities [Member] | U.S. Small Cap [Memeber]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 1 [Member] | Equity Securities [Member] | International Blend [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 1 [Member] | Fixed Income Securities [Member] | Short-Term Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 1 [Member] | Fixed Income Securities [Member] | High Yield Bond [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 1 [Member] | Fixed Income Securities [Member] | Long Duration Bond [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 1 [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 1 [Member] | Insurance Continuance Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	288,835	220,167
Level 2 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 2 [Member] | Equity Securities [Member] | U.S. Large Cap [Memeber]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	96,258	68,671
Level 2 [Member] | Equity Securities [Member] | U.S. Mid Cap [Memeber]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	22,741	16,741
Level 2 [Member] | Equity Securities [Member] | U.S. Small Cap [Memeber]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	28,854	21,222
Level 2 [Member] | Equity Securities [Member] | International Blend [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	54,873	44,200
Level 2 [Member] | Fixed Income Securities [Member] | Short-Term Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,789	4,231
Level 2 [Member] | Fixed Income Securities [Member] | High Yield Bond [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15,127	11,587
Level 2 [Member] | Fixed Income Securities [Member] | Long Duration Bond [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	66,193	53,515
Level 2 [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 2 [Member] | Insurance Continuance Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	21,056	18,607
Level 3 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 [Member] | Equity Securities [Member] | U.S. Large Cap [Memeber]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 [Member] | Equity Securities [Member] | U.S. Mid Cap [Memeber]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 [Member] | Equity Securities [Member] | U.S. Small Cap [Memeber]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 [Member] | Equity Securities [Member] | International Blend [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 [Member] | Fixed Income Securities [Member] | Short-Term Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 [Member] | Fixed Income Securities [Member] | High Yield Bond [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 [Member] | Fixed Income Securities [Member] | Long Duration Bond [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	19,628	17,141	15,565
Level 3 [Member] | Insurance Continuance Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 1,428	$ 1,466	$ 906