Income Taxes (Details) - USD ($) $ in Millions  | 
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2019  | 
Jun. 30, 2018  | 
Jun. 30, 2019  | 
Jun. 30, 2018  | 
|
| Income Tax Disclosure [Abstract] | ||||
| Effective income tax rate | 24.00% | 25.00% | 23.90% | 25.10% | 
| COLO assets fair value increase | $ 1.6 | |||
| X | ||||||||||
- Definition Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
  | 
| X | ||||||||||
- References No definition available. 
  | 
| X | ||||||||||
- Definition Effective Income Tax Rate Reconciliation, Increase in Fair Value of Company Owned Life Insurance Assets No definition available. 
  |