Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	12 Months Ended
	Aug. 07, 2015	Aug. 31, 2015	Jul. 25, 2015	Jul. 26, 2014	Jul. 27, 2013	Sep. 04, 2015	Aug. 25, 2015
Subsequent Event [Line Items]
Number of Shares Repurchased			1,669,924	360,900	1,047,000
Average price per share (in dollars per share)			$ 52.19	$ 27.71	$ 14.52
Payments for repurchase of common stock			$ 87,146	$ 9,999	$ 15,203
TelCom Construction, Inc. | Subsequent Event
Subsequent Event [Line Items]
Payments to acquire business	$ 48,600
Share Repurchase Program July 1, 2015 | Common Stock | Subsequent Event
Subsequent Event [Line Items]
Number of Shares Repurchased		149,224
Average price per share (in dollars per share)		$ 67.01
Payments for repurchase of common stock		$ 10,000
Share Repurchase Program August 25, 2015 | Common Stock | Subsequent Event
Subsequent Event [Line Items]
Number of shares authorized to be repurchased							50,000,000.0
Remaining number of shares authorized to be repurchased						50,000,000.0