Employee Benefit Plan - Summary of Components of Net Periodic Pension Cost (Benefit) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service cost (benefit)	$ 0	$ 230,000	$ 224,000	$ 655,000
Interest cost (benefit)	172,000	164,000	484,000	554,000
Expected return on assets	138,000	(553,000)	(580,000)	(1,778,000)
Amortization of prior service costs (benefit)	0	110,000	0	328,000
Amortization of loss	50,000	5,000	248,000	5,000
Settlement charges	212,000	147,000	606,000	1,110,000
Net periodic pension cost	572,000	103,000	982,000	874,000
Defined Benefit Pension Items
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Reclassification Adjustments, Net of Tax	$ 100,000	$ 300,000	$ 2,100,000	$ 300,000