Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Schedule of Compensation Expense and Related Income Tax Benefit Recognized for All Share-Based Awards

For the years ended December 31, 2020, December 31, 2019, and December 31, 2018, compensation expense and the related income tax benefit recognized for stock options and restricted stock were as follows:

(dollars in thousands)		2020			2019		2018
Compensation Expense		$	7,578		$	8,338	$	8,146
Income Tax Benefit	2,009			2,210			2,160

Schedule of Activity for Restricted Stock

The following table presents the activity for restricted stock:

	Number of Shares			Weighted Average Grant Date Fair Value		Grant Date Fair Value of Restricted Stock that Vested During the Year (in thousands)
Unvested as of December 31, 2017		320,103		$	69.36
Granted		120,173			83.87
Vested		(110,231	)		59.41	$	9,081
Forfeited		(15,558	)		73.82
Unvested as of December 31, 2018		314,487		$	78.17
Granted		130,093			82.82
Vested		(107,759	)		66.46	$	8,910
Forfeited		(26,872	)		83.34
Unvested as of December 31, 2019		309,949		$	83.75
Granted		161,168			80.97
Vested		(99,894	)		84.69	$	8,544
Forfeited		(42,454	)		84.36
Unvested as of December 31, 2020 1		328,769		$	82.02

¹   As of December 31, 2020, 56,362 shares were unvested from service-based grants.

Schedule of Activity for Restricted Stock Units

The following table presents the activity for RSU:

	Number of Units			Weighted Average Grant Date Fair Value		Fair Value of Restricted Stock Unit that Vested During the Year (in thousands)
Balance as of December 31, 2017		116,489		$	60.22
Vested		(62,252	)		57.00	$	5,127
Forfeited		(2,173	)		63.92
Balance as of December 31, 2018		52,064		$	63.92
Vested		(52,064	)		82.23	$	4,311
Balance as of December 31, 2019		—		$	—

Schedule of Activity Related to Stock Options

The following table presents the activity related to stock options under all plans for the year ended December 31, 2020:

	Stock Options				Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)			Aggregate Intrinsic Value (in thousands)
Stock Options Outstanding as of January 1, 2020		237,058			$	45.44
Exercised		(53,004	)			45.99
Stock Options Outstanding as of December 31, 2020		184,054		45.28				1.0		$	5,768
Stock Options Vested and Exercisable as of December 31, 2020		184,054		45.28				1.0	5,768

Summary of Certain Stock Option Activity

The following summarizes certain stock option activity of the Company for the years ended December 31, 2020, December 31, 2019, and December 31, 2018:

(dollars in thousands)		2020			2019			2018
Intrinsic Value of Stock Options Exercised		$	2,261		$	1,106		$	1,634
Cash Received from Stock Options Exercised	2,438			1,473			1,791
Tax Benefits Realized from Stock Options Exercised	485			727			240