Income Taxes (Detail Textuals) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating Loss Carryforwards [Line Items]
Undistributed earnings of the Company's foreign subsidiaries	$ 12,000,000
Deferred tax assets, valuation allowance	83,000	1,003,000
Total net income tax payments (refunds)	122,916,000	158,700,000	90,729,000
Interest and penalties related to the unrecognized tax benefits	276,000	3,000
Bonus depreciation allowance	50.00%
Estimated favorable IRC Section 481(a) adjustments	21,000,000
Tax effect assessment	7,665,000
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards related to state income taxes	11,800,000
Deferred tax assets, valuation allowance	$ 100,000