Capital Stock (Details) $ / shares in Units, $ in Thousands					3 Months Ended			6 Months Ended		12 Months Ended
	May. 20, 2015 USD ($) $ / shares	Apr. 28, 2015 $ / shares shares	Apr. 09, 2015 USD ($) $ / shares	Mar. 05, 2015 $ / shares	Jun. 30, 2015 USD ($) $ / shares shares	Mar. 29, 2015 USD ($) $ / shares shares	Jun. 29, 2014 shares	Jun. 30, 2015 USD ($) $ / shares shares	Jun. 29, 2014 shares	Dec. 28, 2014 USD ($) $ / shares shares	Oct. 13, 2014 USD ($)	Dec. 31, 2012 USD ($) $ / shares shares
Class of Stock [Line Items]
Treasury Stock, Shares					4,064,125			4,064,125		975,594
Preferred stock authorized shares					40,000,000			40,000,000		40,000,000
Preferred stock par value | $ / shares					$ 0.001			$ 0.001		$ 0.001
Demand holder rights percentage												5.00%
Proceeds received greater than | $												$ 100,000
Percent market capitalization greater than												2.50%
Stock Repurchase Program, Authorized Amount | $											$ 400,000
Treasury Stock, Shares, Acquired					371,738	2,806,244				1,101,160
Treasury Stock, Value, Acquired, Cost Method | $					$ 20,026	$ 165,174		$ 185,200		$ 68,000
Treasury Stock, Shares, Acquired and Not Yet Settled					215,017					125,566
Treasury Stock, Value, Acquired and Not Yet Settled | $					$ 12,000					$ 8,000
Share Price | $ / shares					$ 53.87	$ 58.86				$ 61.58
Stock Repurchase Program, Remaining Authorized Repurchase Amount | $					$ 147,000			$ 147,000
Common Stock, Dividends, Per Share, Declared | $ / shares				$ 6.73
Common stock dividends (USD per share) | $ / shares	$ 0.25		$ 6.73
Dividend on Common Stock and Warrantholder payment | $	$ 24,000		$ 649,000
Class A Common Stock
Class of Stock [Line Items]
Number of shares of common stock issued					99,949,057			99,949,057		95,708,401		78,754,269
Common stock, par value | $ / shares					$ 0.001			$ 0.001		$ 0.001		$ 0.001
Common stock, conversion ratio						1
Number of new shares issued from conversion					2,355,286		200	2,401,409	239,384
Number of shares called by each warrant												1
Number of warrants exercised					1,273,345		592,887	1,694,988	3,372,846
Number of shares received					1,273,338		592,883	1,694,981	3,372,816
Class A common stock reserved for issuance					6,668			6,668
Common stock, shares authorized					1,000,000,000			1,000,000,000		1,000,000,000
Shares Sold During Public Offering, Including Existing Shareholders		9,240,073
Shares Issued, Price Per Share | $ / shares		$ 56.00
Class B Common Stock
Class of Stock [Line Items]
Number of shares of common stock issued					36,674			36,674		2,438,083		4,455,767
Common stock, par value | $ / shares					$ 0.001			$ 0.001		$ 0.001		$ 0.001
Common stock, conversion ratio						1
Number of shares converted					2,355,286		200	2,401,409	239,384
Number of shares called by each warrant												1
Number of warrants exercised							0	0	100
Number of shares received									100
Common stock, shares authorized					1,000,000,000			1,000,000,000		200,000,000
Preferred Stock
Class of Stock [Line Items]
Preferred stock authorized shares					40,000,000			40,000,000
Warrant
Class of Stock [Line Items]
Warrants issued					314,973			314,973				16,789,972
Warrant, exercise price, per share | $ / shares												$ 0.001