Other Assets (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Cash surrender value of the COLI	$ 5,800,000	$ 8,600,000
Entity surrender value	5,756,000	0	0
Increase (decrease) in cash surrender value	200,000	700,000	300,000
Payments to acquire marketable securities	2,936,000	0	24,000
Fair value of investments	100,000	100,000
Investments held in Rabbi Trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Entity surrender value	2,900,000
Fair value of investments	5,800,000
Fair value of investments	6,500,000	3,300,000
Unrealized gain on investments	700,000	400,000
Supplemental Employee Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation	14,205,000	10,830,000	11,045,000
Value of assets earmarked for SERP use but not restricted to that use	12,300,000	11,900,000
Payments to acquire marketable securities	$ 2,900,000