Note 9 - Shareholders' Equity (Detail) - Information about stock options granted (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
$40 - $45 [Member]
Options Outstanding, Number Outstanding at 12/31/12	297
Options Outstanding, Aggregate Intrinsic Value (in Dollars)	$ 265
Options Outstanding, Weighted Average Remaining Contractual Life (yrs)	3 years
Options Outstanding, Weighted Average Exercise Price (in Dollars per share)	$ 42
Options Exercisable, Number Outstanding at 12/31/12	297
Options Exercisable, Aggregate Intrinsic Value (in Dollars)	265
Options Exercisable, Weighted Average Remaining Contractual Life (yrs)	3 years
Options Exercisable, Weighted Average Exercise Price (in Dollars per share)	$ 42
$45 - $50 [Member]
Options Outstanding, Number Outstanding at 12/31/12	854
Options Outstanding, Weighted Average Remaining Contractual Life (yrs)	4 years 255 days
Options Outstanding, Weighted Average Exercise Price (in Dollars per share)	$ 48
Options Exercisable, Number Outstanding at 12/31/12	580
Options Exercisable, Weighted Average Remaining Contractual Life (yrs)	2 years 219 days
Options Exercisable, Weighted Average Exercise Price (in Dollars per share)	$ 49
$50 - $55 [Member]
Options Outstanding, Number Outstanding at 12/31/12	935
Options Outstanding, Weighted Average Remaining Contractual Life (yrs)	4 years 292 days
Options Outstanding, Weighted Average Exercise Price (in Dollars per share)	$ 52
Options Exercisable, Number Outstanding at 12/31/12	768
Options Exercisable, Weighted Average Remaining Contractual Life (yrs)	4 years 36 days
Options Exercisable, Weighted Average Exercise Price (in Dollars per share)	$ 52
$55 - $60 [Member]
Options Outstanding, Number Outstanding at 12/31/12	242
Options Outstanding, Weighted Average Remaining Contractual Life (yrs)	7 years
Options Outstanding, Weighted Average Exercise Price (in Dollars per share)	$ 57
Options Exercisable, Number Outstanding at 12/31/12	162
Options Exercisable, Weighted Average Remaining Contractual Life (yrs)	6 years 328 days
Options Exercisable, Weighted Average Exercise Price (in Dollars per share)	$ 57
$40 - $60 [Member]
Options Outstanding, Number Outstanding at 12/31/12	2,328
Options Outstanding, Aggregate Intrinsic Value (in Dollars)	265
Options Outstanding, Weighted Average Remaining Contractual Life (yrs)	4 years 292 days
Options Outstanding, Weighted Average Exercise Price (in Dollars per share)	$ 50
Options Exercisable, Number Outstanding at 12/31/12	1,807
Options Exercisable, Aggregate Intrinsic Value (in Dollars)	$ 265
Options Exercisable, Weighted Average Remaining Contractual Life (yrs)	3 years 255 days
Options Exercisable, Weighted Average Exercise Price (in Dollars per share)	$ 50