Shareholders’ Equity (Stock Option and Restricted Stock Award Activity) (Details) - USD ($)	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Shares Underlying Stock Options
Outstanding beginning balance, Shares underlying stock options and restricted stock awards (in shares)	6,037,302	2,627,462	2,318,685
Granted, Shares underlying stock options and restricted stock awards (in shares)	1,978,219	3,704,725	483,200
Exercised, Shares underlying stock options and restricted stock awards (in shares)	(106,370)	(174,628)	(17,548)
Forfeited, Shares underlying stock options and restricted stock awards (in shares)	(1,442,937)	(120,257)	(156,875)
Outstanding ending balance, Shares underlying stock options and restricted stock awards (in shares)	6,466,214	6,037,302	2,627,462
Vested and expected to vest ending balance, Shares underlying stock options (in shares)	6,466,214
Exercisable ending balance, Shares underlying stock options (in shares)	3,118,365
Weighted- average Exercise Price per Share
Outstanding beginning balance, Weighted - average exercise price (in dollars per share)	$ 24.19	$ 21.07	$ 22.01
Granted, Weighted - average exercise price (in dollars per share)	23.66	25.94	17.83
Exercised, Weighted - average exercise price (in dollars per share)	17.95	15.42	8.52
Forfeited, Weighted - average exercise price (in dollars per share)	28.07	22.82	26.35
Outstanding ending balance, Weighted - average exercise price (in dollars per share)	23.26	$ 24.19	$ 21.07
Vested and expected to vest ending balance, Weighted - average exercise price (in dollars per share)	23.26
Exercisable ending balance, Weighted - average exercise price (in dollars per share)	$ 22.61
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Outstanding ending balance, Weighted - average remaining contractual term (yrs)	7 years 7 months 25 days
Outstanding ending balance, Aggregate intrinsic value	$ 200,279
Vested and expected to vest ending balance, Weighted - average remaining contractual term (yrs)	7 years 7 months 25 days
Vested and expected to vest ending balance, Aggregate intrinsic value	$ 200,279
Exercisable ending balance, Weighted - average remaining contractual term (yrs)	6 years 4 months
Exercisable ending balance, Aggregate intrinsic value	$ 200,279

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Gross number of share options (or share units) granted during the period.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Number of fully vested and expected to vest options outstanding that can be converted into shares under option plan. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted-average exercise price, at which grantee can acquire shares reserved for issuance, for fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of share options (or share units) exercised during the current period.

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