Annual and transition report of foreign private issuers pursuant to Section 13 or 15(d)

Subsequent events (Details)

v3.8.0.1
Subsequent events (Details) - Subsequent Event [Member] - USD ($)
Mar. 02, 2018
Jan. 31, 2018
Subsequent Event [Line Items]    
Share repurchase, remaining amount under the program $ 145,700,000  
Senior Notes [Member] | AGAT/AICDC Notes Due 2023 [Member]    
Subsequent Event [Line Items]    
Face amount   $ 600,000,000
Stated interest rate   3.30%
Senior Notes [Member] | AGAT/AICDC Notes Due 2028 [Member]    
Subsequent Event [Line Items]    
Face amount   $ 550,000,000
Stated interest rate   3.875%