CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 59,689	$ 66,405
Series A preferred stock, par value (in USD per share)	$ 0.0001	$ 0
Series A preferred stock, shares authorized (in shares)	825,000	0
Series A preferred stock, shares issued (in shares)	635,822	0
Series A preferred stock, shares outstanding (in shares)	635,822	0
Series A preferred stock, liquidation preference	$ 69,702	$ 0
Preferred stock, par value (in USD per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	4,175,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in USD per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	125,000,000	125,000,000
Common stock, shares issued (in shares)	71,421,664	71,274,064
Common stock, shares outstanding (in shares)	68,767,613	68,636,965
Treasury stock (in shares)	2,654,051	2,637,099