Shareholders Equity and Stock Options (Performance Based Restricted Stock Awards) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Outstanding at period beginning, weighted average grant date fair value	$ 40.58	$ 37.54	$ 36.63
Awards granted, weighted average grant date fair value	$ 0.00	$ 41.27	$ 46.29
Stock issued, weighted average grant date fair value	$ 37.82	$ 42.97	$ 33.61
Awards forfeited or expired, weighted average grant date fair value	$ 39.04	$ 43.57	$ 30.77
Outstanding at period end, weighted average grant date fair value	$ 43.23	$ 40.58	$ 37.54
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Non-vested awards outstanding, beginning balance	73,458	101,730	115,250
Awards granted	47,625	22,120	20,630
Stock issued	(33,538)	(43,750)	0
Awards forfeited or expired	(16,370)	(6,642)	(34,150)
Non-vested awards outstanding, ending balance	71,175	73,458	101,730
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Outstanding at period beginning, weighted average grant date fair value	$ 38.01	$ 31.19	$ 27.09
Awards granted, weighted average grant date fair value	$ 47.10	$ 41.27	$ 47.89
Stock issued, weighted average grant date fair value	$ 27.43	$ 23.86	$ 0.00
Awards forfeited or expired, weighted average grant date fair value	$ 44.90	$ 37.67	$ 27.43
Outstanding at period end, weighted average grant date fair value	$ 47.49	$ 38.01	$ 31.19