Equity Incentive Compensation Plans (Restricted Stock Units and Performance Share Program) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Restricted Stock Units
Other than stock options activity
Outstanding at the beginning of the period (in shares)	857,360	[1],[2]	1,107,293	[1],[2]	966,198
Granted (in shares)	159,333		34,529		294,504
Issued (in shares)	(62,127)		(246,633)		(107,375)
Canceled/expired (in shares)	(39,544)		(37,829)		(46,034)
Outstanding at the end of the period (in shares)	915,022	[1],[2]	857,360	[1],[2]	1,107,293	[1],[2]
Weighted-average intrinsic value at grant-date
Outstanding at the beginning of the period (in dollars per share)	$ 19.67	[1],[2]	$ 22.14	[1],[2]	$ 20.83
Granted (in dollars per share)	$ 47.98		$ 30.94		$ 26.72
Issued (in dollars per share)	$ 26.18		$ 28.98		$ 28.98
Canceled/expired (in dollars per share)	$ 25.12		$ 22.20		$ 25.08
Outstanding at the end of the period (in dollars per share)	$ 23.88	[1],[2]	$ 19.67	[1],[2]	$ 22.14	[1],[2]
Vest Date Fair Value - Issued (in dollars)	$ 2,588		$ 7,813		$ 2,574
Performance-Based RSUs
Other than stock options activity
Outstanding at the beginning of the period (in shares)	103,794		0		0
Granted (in shares)	65,620		103,794		0
Issued (in shares)	0		0		0
Canceled/expired (in shares)	(6,565)		0		0
Outstanding at the end of the period (in shares)	162,849		103,794		0
Weighted-average intrinsic value at grant-date
Outstanding at the beginning of the period (in dollars per share)	$ 31.20		$ 0.00		$ 0.00
Granted (in dollars per share)	$ 51.86		$ 31.20		$ 0.00
Issued (in dollars per share)	$ 0.00		$ 0.00		$ 0.00
Canceled/expired (in dollars per share)	$ 44.20		$ 0.00		$ 0.00
Outstanding at the end of the period (in dollars per share)	$ 39.00		$ 31.20		$ 0.00
Vest Date Fair Value - Issued (in dollars)	$ 0		$ 0		$ 0

[1] The balance outstanding includes RSUs granted to executive officers and other officers that have vested in accordance with the RSU agreement, but are subject to a deferral election before the corresponding shares of Common Stock are issued. For the years ended December 31, 2011, 2010 and 2009, 483,908, 289,335, and 124,799 RSUs have vested, but the corresponding shares of Common Stock have not been issued.

[2] The balance outstanding includes RSUs granted to the non-employee directors that 100% vested at date of grant but are subject to a deferral election before the corresponding shares of Common Stock are issued. For the years ended December 31, 2011, 2010 and 2009, 30,544, 10,522 and 10,522 RSUs have vested, but the corresponding shares of Common Stock have not been issued.