Note 7 - Share-based Compensation - Nonvested Award Activity (Details) - Stock Unit Award [Member] - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Outstanding & Unvested (in shares)		74
Outstanding & Unvested, weighted average price per share (in dollars per share)	[1]	$ 14.62
Outstanding & Unvested, weighted average fair value	[1]	$ 516	$ 1,077
Granted (in shares)		13
Granted, weighted average price per share (in dollars per share)	[1]	$ 18.87
Granted, weighted average fair value	[1]	$ 236
Converted to common stock (in shares)		(10)
Converted to common stock, weighted average price per share (in dollars per share)		$ 13.84
Converted to common stock, weighted average fair value	[1]	$ (138)
Cancelled (in shares)		(15)
Cancelled, weighted average price per share (in dollars per share)		$ 16.15
Cancelled, weighted average fair value	[1]	$ (241)
Forfeited (in shares)		(29)
Forfeited, weighted average price per share (in dollars per share)		$ 14.25
Forfeited, weighted average fair value	[1]	$ (418)
Outstanding & Unvested (in shares)		33
Outstanding & Unvested, weighted average price per share (in dollars per share)	[1]	$ 16.08

[1] Weighted average price per share is the weighted grant price based on the closing market price of each of the stock grants related to each transaction type. The Weighted average fair value is the weighted average share price times the number of shares.