Income Taxes - Reconciliation of US Statutory Federal Tax Rate (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Disclosure Income Tax Reconciliation Of U S Statutory Federal Tax Rate Detail [Line Items]
US federal statutory rate	35.00%	35.00%	35.00%	35.00%
Non-US income taxed at different rates	(13.00%)	(11.00%)	(12.00%)	(11.00%)
Other	(1.00%)	(2.00%)	(2.00%)	(2.00%)
Effective income tax rate	21.00%	22.00%	22.00%	22.00%
Charges And Credits
Disclosure Income Tax Reconciliation Of U S Statutory Federal Tax Rate Detail [Line Items]
Charges and credits (See Note 2)			1.00%