Consolidated balance sheets (Parenthetical) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
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 (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	192,130,071	192,130,071
Common stock, shares issued	48,413,185	46,651,616
Common stock, shares outstanding	47,942,230	46,390,513
Treasury stock, shares	470,955	261,103