| Consolidated Statements of Shareholders' Equity Consolidated Statements of Shareholders' Equity (Parenthetical) - $ / shares | 12 Months Ended | ||
|---|---|---|---|
| Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
| Dividends per share (in dollars per share) | $ 0.63 | $ 0.60 | $ 0.51 | 
| X | ||||||||||
| 
- Definition Aggregate dividends declared during the period for each share of common stock outstanding. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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