CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement of Stockholders' Equity [Abstract]
Tax benefit (expense) on change in retirement obligations, tax	$ 1,385	$ 1,647	$ 4,222
Tax benefit from change on derivatives designated as cash flow hedges, tax	2,692	2,791	12,500
Repurchase of common stock, shares	2,916,280	2,182,946
Issuance of common stock from issuance of unvested shares, exercise of stock options and deferred compensation plans, shares	1,471,568	1,826,977	1,596,145
Issuance of common stock from issuance of unvested shares, exercise of stock options and deferred compensation plans, tax	$ 4,514	$ 4,865	$ 4,150
Cash dividends declared, per common share outstanding	$ 0.89	$ 0.8	$ 0.68