Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Tax Disclosure [Abstract]
Income tax expense (benefit)	$ 21,793	$ 21,660	$ 44,255	$ 42,297
Effective income tax rate			31.54%	31.60%