Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2016

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Summary of Stock-Based Compensation Expense

Stock-based compensation expense is summarized as follows:

	Years Ended December 31,
	2016		2015		2014
($ in thousands)
Stock-based compensation expense	$	11,948	$	11,863	$	9,778

Summary of Restricted Stock Units Activity

RSU activity for the year ended December 31, 2016 is summarized as follows:

	Number of shares		Weighted Average Grant Date Fair Value
Outstanding at December 31, 2015	191,617		$	156.66
Granted	178,333		$	80.33
Forfeited	(11,502	)	$	109.64
Settled	(55,624	)	$	167.23
Outstanding at December 31, 2016	302,824		$	111.56

Summary of Stock Option Activity

Stock option activity for the year ended December 31, 2016 is summarized as follows:

	Number of shares		Weighted Average Exercise Price
Outstanding at December 31, 2015	156,636		$	18.78
Granted	—		$	—
Exercised	(19,479	)	$	25.89
Forfeited	—		$	—
Outstanding at December 31, 2016	137,157		$	17.77
Vested and exercisable at December 31, 2016	137,157		$	17.77