Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Net of allowance on accounts receivable	$ 30,414	$ 27,862
Preferred stock, par value
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value
Common stock, shares authorized	70,000,000	70,000,000
Common stock, shares outstanding	32,572,000	32,353,000