STOCK-BASED COMPENSATION (Details - RSU and RSA Rollforwards) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
RSUs
Nonvested RSUs and RSAs, Number of Shares
Nonvested at the beginning of the period (in shares)	351,801
Granted (in shares)	101,955
Vested (in shares)	(187,052)
Forfeited (in shares)	(29,327)
Nonvested at the end of the period (in shares)	237,377	351,801
Nonvested RSUs and RSAs, Weighted Average Grant Date Fair Value
Nonvested at the beginning of the period (in dollars per share)	$ 22.83
Granted (in dollars per share)	69.35
Vested (in dollars per share)	20.83
Forfeited (in dollars per share)	32.92
Nonvested at the end of the period (in dollars per share)	$ 43.13	$ 22.83
Fair value of RSUs and RSAs that vested during the year	$ 11.0	$ 11.0	$ 7.5
Restricted Stock
Nonvested RSUs and RSAs, Number of Shares
Nonvested at the beginning of the period (in shares)	123,057
Granted (in shares)	0
Vested (in shares)	(54,295)
Nonvested at the end of the period (in shares)	68,762	123,057
Nonvested RSUs and RSAs, Weighted Average Grant Date Fair Value
Nonvested at the beginning of the period (in dollars per share)	$ 23.41
Granted (in dollars per share)	0.00
Vested (in dollars per share)	23.18
Nonvested at the end of the period (in dollars per share)	$ 23.60	$ 23.41
Fair value of RSUs and RSAs that vested during the year	$ 4.1	$ 1.5	$ 3.2