XML 31 R20.htm IDEA: XBRL DOCUMENT v3.19.1
Summary of Significant Accounting Policies - Retained Deficit (Details)
$ in Millions
Mar. 31, 2019
USD ($)
Retained Earnings (Accumulated Deficit) [Abstract]  
Cumulative share repurchases $ 1,449.9
Cumulative dividends $ 512.9