Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	58,453,283	57,119,873
Common stock, shares outstanding	57,331,022	57,119,873
Treasury stock, shares	1,122,261	0