XML 45 R31.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Share Repurchase Program (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2018
Proceeds from (Repurchase of) Equity [Abstract] |
Schedule of shares repurchased |
| For the Year Ended December 31,
| 2018 |  | 2017
Shares repurchased | 6,061 |  |  | 9,301 |
Average price per share | $ | 282.80 |  |  | $ | 233.57 |
Total investment | $ | 1,713,953 |  |  | $ | 2,172,437 |

X
- References No definition available. + Details
Name: | us-gaap_ProceedsFromRepurchaseOfEquityAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of treasury stock, including, but not limited to, average cost per share, description of share repurchase program, shares repurchased, shares held for each class of treasury stock. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6405834&loc=d3e23309-112656 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6405834&loc=d3e23315-112656 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6405834&loc=d3e23285-112656 + Details
Name: | us-gaap_ScheduleOfTreasuryStockByClassTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration