Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 3,761	$ 4,246
Long-term debt, current maturities and loan origination fees	638	787
Notes payable, premium	2,978
Notes payable, debt issuance costs	$ 9,308	$ 5,464
Preferred stock, no par value (in dollars per share)	$ 0	$ 0
Preferred stock, shares authorized	250	250
Preferred stock, shares issued	0	0
Common stock, no par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized	50,000	50,000
Common stock, shares issued	16,600	17,472