Equity (Aggregate Shares Purchased) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Equity [Abstract]
Board of Directors authorized to purchase shares	2,500,000
Shares purchased under 2013 and 2001 authorization	966,700	576,064	435,000
Aggregate amount	$ 46,052	$ 22,509	$ 19,576
Average price paid per share	$ 47.64	$ 39.07	$ 45.00