Note 7 - Earnings Per Share ("EPS") (Details Textual) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended		6 Months Ended
	Jun. 30, 2016	Feb. 29, 2016	Feb. 26, 2016	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Accelerated Stock Repurchase [Member] | Morgan Stanley & Co., LLC [Member] | Common Stock [Member]
Stock Repurchase Program, Authorized Amount			$ 25,000
Accelerated Share Repurchases, Initial Price Paid Per Share		$ 46.40
Stock Repurchase Program, Percentage Repurchased		70.00%
Accelerated Stock Repurchase [Member] | Morgan Stanley & Co., LLC [Member] | Additional Paid-in Capital [Member]
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 7,500			$ 7,500		$ 7,500
Accelerated Stock Repurchase [Member] | Morgan Stanley & Co., LLC [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	200,000
Payments for Repurchase of Common Stock			$ 25,000
Stock Repurchased and Retired During Period, Shares		377,155
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount				300,000	200,000	300,000	200,000
Payments for Repurchase of Common Stock						$ 25,000