Share-based payments (Tables)

12 Months Ended

Dec. 31, 2019

Share-based Payment Arrangement [Abstract]

Summary of the restricted common stock award/unit activity

A summary of the restricted common stock award activity during the year ended December 31, 2019 is presented below:

	Shares		Weighted-Average Grant-Date Fair Value per Share ($)
Nonvested balance at January 1, 2019	120,276		40.99
Granted	13,702		41.26
Adjustment for performance-based shares	(40,297	)	42.32
Vested	(33,532	)	39.82
Forfeited	(6,760	)	42.50
Nonvested balance at December 31, 2019	53,389		40.60

A summary of the restricted common stock unit activity during the year ended December 31, 2019 is presented below:

	Units		Weighted-Average Grant-Date Fair Value per Share ($)
Nonvested balance at January 1, 2019	123,841		42.67
Granted	122,358		42.02
Vested	(17,003	)	42.14
Forfeited	(33,179	)	43.21
Nonvested balance at December 31, 2019	196,017		42.21