Income Taxes (Summary of Changes in Gross Amount of Unrecognized Tax Benefits) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued [Abstract]
Balance as of January 1,	$ 50,459	$ 51,004	$ 45,800	$ 36,710
Additions based on tax positions related to the current year		7,046	8,100	7,308
Additions based on tax positions related to prior years			1,301	4,060
Payments related to settled items		(1,056)	(451)
Reduction due to lapse of statute of limitations (with 2014 estimate)	(4,300)	(6,535)	(3,746)	(2,278)
Balance as of December 31,		$ 50,459	$ 51,004	$ 45,800