Shareholders' Equity Cash Dividends Declared Per Common Share (Details) - $ / shares |
3 Months Ended | 6 Months Ended | ||
---|---|---|---|---|
Jun. 30, 2017 |
Jun. 30, 2016 |
Jun. 30, 2017 |
Jun. 30, 2016 |
|
Equity [Abstract] | ||||
Cash dividends declared and paid per common share (in dollars per share) | $ 0.58 | $ 0.55 | $ 1.16 | $ 1.1 |