Employee Benefit Plans (Fair Value of the Company’s Qualified Pension Plan Assets by Category) (Details) (Pension Plans, Defined Benefit, USD $)	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Defined Benefit Plans and Other Postretirement Benefit Plans
Fair value of qualified plan assets	$ 46,547,000		$ 43,852,000		$ 49,537,000
Defined Benefit Plan, Accumulated Benefit Obligation	50,700,000		49,000,000
Equity Securities
Defined Benefit Plans and Other Postretirement Benefit Plans
Fair value of qualified plan assets	26,067,000	[1]	25,844,000	[2]
Fixed Income Funds
Defined Benefit Plans and Other Postretirement Benefit Plans
Fair value of qualified plan assets	20,022,000	[3]	17,439,000	[4]
Cash and Cash Equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans
Fair value of qualified plan assets	458,000	[5]	569,000	[5]
Equity Securities, Large Company
Defined Benefit Plans and Other Postretirement Benefit Plans
Defined Benefit Plan, Actual Plan Asset Allocations (as a percentage)	53.30%		54.50%
Equity Securities, Small Company
Defined Benefit Plans and Other Postretirement Benefit Plans
Defined Benefit Plan, Actual Plan Asset Allocations (as a percentage)	11.60%		15.40%
Equity Securities, Medium Company
Defined Benefit Plans and Other Postretirement Benefit Plans
Defined Benefit Plan, Actual Plan Asset Allocations (as a percentage)	12.80%		12.00%
Equity Securities, Foreign Company
Defined Benefit Plans and Other Postretirement Benefit Plans
Defined Benefit Plan, Actual Plan Asset Allocations (as a percentage)	17.20%		14.40%
Equity Securities, Other Companies
Defined Benefit Plans and Other Postretirement Benefit Plans
Defined Benefit Plan, Actual Plan Asset Allocations (as a percentage)			3.70%
Equity Funds
Defined Benefit Plans and Other Postretirement Benefit Plans
Defined Benefit Plan, Actual Plan Asset Allocations (as a percentage)	5.10%
Equity Securities, Other
Defined Benefit Plans and Other Postretirement Benefit Plans
Defined Benefit Plan, Actual Plan Asset Allocations (as a percentage)	11.60%		15.50%
Equity Securities, Mutual Funds
Defined Benefit Plans and Other Postretirement Benefit Plans
Defined Benefit Plan, Actual Plan Asset Allocations (as a percentage)	86.50%		82.80%
Exchange Traded Funds
Defined Benefit Plans and Other Postretirement Benefit Plans
Defined Benefit Plan, Actual Plan Asset Allocations (as a percentage)	1.90%		1.70%
Quoted prices in active markets for identical assets (Level 1)
Defined Benefit Plans and Other Postretirement Benefit Plans
Fair value of qualified plan assets	46,547,000		43,852,000
Quoted prices in active markets for identical assets (Level 1) | Equity Securities
Defined Benefit Plans and Other Postretirement Benefit Plans
Fair value of qualified plan assets	26,067,000	[1]	25,844,000	[2]
Quoted prices in active markets for identical assets (Level 1) | Fixed Income Funds
Defined Benefit Plans and Other Postretirement Benefit Plans
Fair value of qualified plan assets	20,022,000	[3]	17,439,000	[4]
Quoted prices in active markets for identical assets (Level 1) | Cash and Cash Equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans
Fair value of qualified plan assets	458,000	[5]	569,000	[5]
Significant observable inputs (Level 2)
Defined Benefit Plans and Other Postretirement Benefit Plans
Fair value of qualified plan assets	0		0
Significant observable inputs (Level 2) | Equity Securities
Defined Benefit Plans and Other Postretirement Benefit Plans
Fair value of qualified plan assets	0	[1]	0	[2]
Significant observable inputs (Level 2) | Fixed Income Funds
Defined Benefit Plans and Other Postretirement Benefit Plans
Fair value of qualified plan assets	0	[3]	0	[4]
Significant observable inputs (Level 2) | Cash and Cash Equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans
Fair value of qualified plan assets	0	[5]	0	[5]
Significant unobservable inputs (Level 3)
Defined Benefit Plans and Other Postretirement Benefit Plans
Fair value of qualified plan assets	0		0
Significant unobservable inputs (Level 3) | Equity Securities
Defined Benefit Plans and Other Postretirement Benefit Plans
Fair value of qualified plan assets	0	[1]	0	[2]
Significant unobservable inputs (Level 3) | Fixed Income Funds
Defined Benefit Plans and Other Postretirement Benefit Plans
Fair value of qualified plan assets	0	[3]	0	[4]
Significant unobservable inputs (Level 3) | Cash and Cash Equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans
Fair value of qualified plan assets	$ 0	[5]	$ 0	[5]

[1] This category includes investments in equity securities of large, small and medium sized companies, equity securities of foreign companies and equity funds, or 53.3%, 11.6%, 12.8%, 17.2% and 5.1% of total equity securities, respectively. Of the total equity amount, 11.6% was invested in common stocks in a wide variety of industries, 86.5% was invested in mutual funds and 1.9% was invested in exchange traded funds. The funds are valued using the closing market prices at December 31, 2012.

[2] This category includes investments in equity securities of large, small and medium sized companies, equity securities of foreign companies and other, or 54.5%, 15.4%, 12.0%, 14.4% and 3.7% of total assets, respectively. Of the total equity amount, 15.5% was invested in common stocks in a wide variety of industries, 82.8% was invested in mutual funds and 1.7% was invested in exchange traded funds. The funds are valued using the closing market prices at December 31, 2011

[3] This category includes investments in investment-grade fixed-income instruments and corporate bonds. The funds are valued using the closing market prices at December 31, 2012

[4] This category includes investments in investment-grade fixed-income instruments and corporate bonds. The funds are valued using the closing market prices at December 31, 2011

[5] This category comprises the cash held to pay beneficiaries. The fair value of cash equals its book value