Defined Contribution Bonus and Profit Sharing Plans Schedule of Defined Contribution Plans Expense (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Defined contribution plans expense	$ 7,097	$ 7,392	$ 7,551