Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands, None in scaling factor is -9223372036854775296	Jun. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Accounts and other receivables, allowance for doubtful accounts and sales returns	$ 2,830	$ 2,610
Common stock, no par value
Common stock, shares issued	32,705,198	32,422,082
Common stock, shares outstanding	32,705,198	32,422,082
Common Stock, Shares Held in Employee Trust, Shares	66,823	66,255