Retirement Pension Plan - Schedule of Weighted Average Assets Allocations (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Weighted-average assets allocations	100.00%	100.00%	100.00%
Target plan asset allocations for 2013	40.00%
Preferred securities
Defined Benefit Plan Disclosure [Line Items]
Weighted-average assets allocations	73.50%	70.10%	63.50%
Target plan asset allocations for 2013	60.00%
Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Weighted-average assets allocations	25.00%	27.60%	34.90%
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Weighted-average assets allocations	1.50%	2.30%	1.60%
Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Weighted-average assets allocations	0.00%	0.00%	0.00%