CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Accounts receivable, allowance (in dollars)	$ 10,898	$ 12,487
Preferred stock, par value (in dollars per share)	$ 0	$ 0
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	2,764,000	2,427,000
Preferred stock, shares outstanding (in shares)	2,763,835	2,426,930
Preferred stock, redemption amount	$ 69,096	$ 60,273
Common stock and additional paid-in capital, par value (in dollars per share)	$ 0	$ 0
Common stock and additional paid-in capital, shares authorized (in shares)	55,000,000	55,000,000
Common stock and additional paid-in capital, shares issued (in shares)	19,892,000	19,861,000
Common stock and additional paid-in capital, shares outstanding (in shares)	19,892,000	19,861,000