Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	40,840,685	40,635,233
Common stock, shares outstanding	34,261,920	34,056,468
Treasury stock, shares	6,578,765	6,578,765