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Employee Share-Based Incentive Compensation Plans WTM Stock options (Details) - USD ($) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2017 | Mar. 31, 2016 | Dec. 31, 2016
Share-based compensation arrangement by share-based payment award |  |  |
Shares Issued, Price Per Share |  |  | $ 742
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements |  | 882 |
Employee Stock Option [Member] |  |  |
Share-based compensation arrangement by share-based payment award |  |  |
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements |  | 125,000 |
Common Stock [Member] |  |  |
Share-based compensation arrangement by share-based payment award |  |  |
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements | 5,142 |  |
Chief Executive Officer | Employee Stock Option [Member] |  |  |
Share-based compensation arrangement by share-based payment award |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value | $ 4,400,000 |  |
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Exercised | 125,000 |  |
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements | 40,000 |  |
Combination Two | Employee Stock Option [Member] |  |  |
Share-based compensation arrangement by share-based payment award |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value |  |  | $ 8,400,000
Conversion of Stock, Shares Converted |  |  | 9,930
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements |  |  | 80,000
Combination One | Employee Stock Option [Member] |  |  |
Share-based compensation arrangement by share-based payment award |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value |  |  | $ 400,000
Shares Issued, Price Per Share |  |  | $ 742
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements |  |  | 5,000

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- Definition The number of shares converted in a noncash (or part noncash) transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4332-108586 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4304-108586 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4313-108586 + Details
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- Definition Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 45 -Paragraph 28A -URI http://asc.fasb.org/extlink&oid=64863997&loc=d3e1500-109256 + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition Number of non-option equity instruments exercised by participants. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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