Income Taxes (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Provision for income taxes	$ 29,613,000	$ 27,886,000	$ 58,141,000	$ 52,568,000
Effective tax rate	26.10%	26.90%	26.70%	26.80%
Minimum
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Reasonably possible change in unrecognized tax benefits over next 12 months	$ 0		$ 0
Maximum
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Reasonably possible change in unrecognized tax benefits over next 12 months	$ 2,300,000		$ 2,300,000