Employee Benefit Plans (Details 7)	12 Months Ended
	Dec. 31, 2012
Fixed income investments - Cash/money market account
Targeted percentage of plan assets	2.00%
Targeted percentage of plan assets, minimum	1.00%
Targeted percentage of plan assets, maximum	5.00%
Fixed income investments - US government bond fund
Targeted percentage of plan assets	10.00%
Targeted percentage of plan assets, minimum	10.00%
Targeted percentage of plan assets, maximum	20.00%
Fixed income investments - US corporate bond fund
Targeted percentage of plan assets	10.00%
Targeted percentage of plan assets, minimum	5.00%
Targeted percentage of plan assets, maximum	15.00%
Fixed income investments - US corporate high yield bond fund
Targeted percentage of plan assets	5.00%
Targeted percentage of plan assets, minimum	0.00%
Targeted percentage of plan assets, maximum	10.00%
Equity investments - Large cap value fund
Targeted percentage of plan assets	20.00%
Targeted percentage of plan assets, minimum	20.00%
Targeted percentage of plan assets, maximum	30.00%
Equity investments - Large cap growth fund
Targeted percentage of plan assets	20.00%
Targeted percentage of plan assets, minimum	20.00%
Targeted percentage of plan assets, maximum	30.00%
Equity investments - Mid cap equity fund
Targeted percentage of plan assets	10.00%
Targeted percentage of plan assets, minimum	5.00%
Targeted percentage of plan assets, maximum	15.00%
Equity investments - Small cap growth fund
Targeted percentage of plan assets	8.00%
Targeted percentage of plan assets, minimum	5.00%
Targeted percentage of plan assets, maximum	15.00%
Equity investments - Foreign equity fund
Targeted percentage of plan assets	10.00%
Targeted percentage of plan assets, minimum	5.00%
Targeted percentage of plan assets, maximum	15.00%
Equity investments - Company stock
Targeted percentage of plan assets	5.00%
Targeted percentage of plan assets, minimum	0.00%
Targeted percentage of plan assets, maximum	10.00%