Employee Benefit Plans (Details 9) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Fair Value Total
Fair value of plan assets	$ 30,124	$ 24,466
Significant Other Observable Inputs (Level 2)
Fair value of plan assets	441	831
Quoted Prices in Market for Identical Assets (Level 1)
Fair value of plan assets	29,683	23,635
Fixed income investments - Money market funds | Fair Value Total
Fair value of plan assets	441	831
Fixed income investments - Money market funds | Significant Other Observable Inputs (Level 2)
Fair value of plan assets	441	831
Fixed income investments - US government bond fund | Fair Value Total
Fair value of plan assets	2,995	2,356
Fixed income investments - US government bond fund | Quoted Prices in Market for Identical Assets (Level 1)
Fair value of plan assets	2,995	2,356
Fixed income investments - US corporate bond fund | Fair Value Total
Fair value of plan assets	3,008	2,331
Fixed income investments - US corporate bond fund | Quoted Prices in Market for Identical Assets (Level 1)
Fair value of plan assets	3,008	2,331
Fixed income investments - US corporate high yield bond fund | Fair Value Total
Fair value of plan assets	1,563	1,195
Fixed income investments - US corporate high yield bond fund | Quoted Prices in Market for Identical Assets (Level 1)
Fair value of plan assets	1,563	1,195
Equity investments - Large cap value fund | Fair Value Total
Fair value of plan assets	6,101	5,194
Equity investments - Large cap value fund | Quoted Prices in Market for Identical Assets (Level 1)
Fair value of plan assets	6,101	5,194
Equity investments - Large cap growth fund | Fair Value Total
Fair value of plan assets	6,020	4,883
Equity investments - Large cap growth fund | Quoted Prices in Market for Identical Assets (Level 1)
Fair value of plan assets	6,020	4,883
Equity investments - Small cap growth fund | Fair Value Total
Fair value of plan assets	2,514	2,030
Equity investments - Small cap growth fund | Quoted Prices in Market for Identical Assets (Level 1)
Fair value of plan assets	2,514	2,030
Equity investments - Mid cap growth fund | Fair Value Total
Fair value of plan assets	3,153	2,491
Equity investments - Mid cap growth fund | Quoted Prices in Market for Identical Assets (Level 1)
Fair value of plan assets	3,153	2,491
Equity investments - Foreign equity fund | Fair Value Total
Fair value of plan assets	3,147	2,328
Equity investments - Foreign equity fund | Quoted Prices in Market for Identical Assets (Level 1)
Fair value of plan assets	3,147	2,328
Equity investments - Company stock | Fair Value Total
Fair value of plan assets	1,182	827
Equity investments - Company stock | Quoted Prices in Market for Identical Assets (Level 1)
Fair value of plan assets	$ 1,182	$ 827