Compensation Plans: Stock Based (Details) (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Compensation plans
Excess income tax benefit from the exercise of stock awards	$ 0		$ 0		$ 854,000
Employee Service Share-bassed Compensation, Cash Received from Exercise, All Grant Types	3,000,000		5,000,000		4,800,000
Stock-based Compensation, Number of Shares Available for Grant Under the Equity Incentive Compensation Program	1,400,000
Impact of Issuance of One Performance Share Award on Available Shares Under the Equity Incentive Plan	2.86
Impact Outright Issuance Of One Share Has On Number Of Available Shares	1.43
Performance Share Units, Restricted Stock Units, and Shares Issued to Directors [Abstract]
Stock-based compensation expense	30,185,000		26,824,000		26,743,000
Employee Stock Purchase Plan
Proceeds from Issuance of Common Stock	5,816,000		7,327,000		6,440,000
Employee Stock [Member]
Compensation plans
Stock-based Compensation, Number of Shares Available for Grant Under the Equity Incentive Compensation Program	1,300,000
Performance Share Units, Restricted Stock Units, and Shares Issued to Directors [Abstract]
Stock-based compensation expense	948,000		682,000		550,000
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate	15.00%
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription	25,000
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date	85.00%
Shares issued (in shares)	66,485		41,358		52,948
Proceeds from Issuance of Common Stock	2,800,000		2,300,000		1,700,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	0.10%		0.20%		0.20%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	0.20%		0.20%		0.30%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate	47.80%		36.30%		46.30%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	6 months		6 months		6 months
Performance Shares [Member]
Compensation plans
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Multiplier Assumed	1
Share-based Compensation, Awards Other Than Options, Performance Measurement Period	3
Performance Share Units, Restricted Stock Units, and Shares Issued to Directors [Abstract]
Stock-based compensation expense	18,200,000		19,700,000		17,700,000
Unrecognized stock based compensation expense	19,600,000
Fair value of PSUs/RSUs Vested in Period	22,100,000		13,000,000		6,600,000
Fair value of PSUs/RSUs Granted in Period	16,400,000		24,300,000		20,300,000
PSU/RSU Vesting Increment	0.33
Shares held for settlement of income and payroll tax obligations (in shares)	406,866		98,955
Total PSUs Settled in Period	609,714
Multiplier Applied to PSU Awards at Settlement	2		0.8
Stock issued for settlement, PSU, net of tax (in shares)	812,562		206,468
Common stock awards vesting multiplier, high end of range	2
Common stock awards vesting multiplier, low end of range	0
Activity
Non-vested at the beginning of the period (in shares)	885,894	[1]	1,110,666	[1]	1,069,090	[1]
Granted (in shares)	314,853	[1]	266,282	[1]	387,651	[1]
Vested (in shares)	(493,679)	[1]	(364,172)	[1]	(210,801)	[1]
Forfeited (in shares)	(37,760)	[1]	(126,882)	[1]	(135,274)	[1]
Non-vested at the end of the period (in shares)	669,308		885,894	[1]	1,110,666	[1]
Weighted Average Grant Date Fair Value
Non-vested outstanding at the beginning of the period (in dollars per share)	$ 57.52	[1]	$ 39.48	[1]	$ 32.52	[1]
Granted (in dollars per share)	$ 51.98	[1]	$ 91.45	[1]	$ 52.35	[1]
Vested (in dollars per share)	$ 44.72	[1]	$ 35.74	[1]	$ 31.18	[1]
Forfeited (in dollars per share)	$ 65.35	[1]	$ 33.32	[1]	$ 34.28	[1]
Non-vested outstanding at the end of the period (in dollars per share)	$ 63.91		$ 57.52	[1]	$ 39.48	[1]
Restricted Stock Units (RSUs) [Member]
Performance Share Units, Restricted Stock Units, and Shares Issued to Directors [Abstract]
Stock-based compensation expense	9,800,000		5,300,000		7,700,000
Unrecognized stock based compensation expense	14,400,000
Fair value of PSUs/RSUs Vested in Period	5,400,000		3,200,000		7,400,000
Fair value of PSUs/RSUs Granted in Period	18,800,000		7,200,000		5,200,000
PSU/RSU Vesting Increment	0.33
Shares held for settlement of income and payroll tax obligations (in shares)	49,857		33,515		47,278
Total PSUs Settled in Period	166,670		105,820		160,381
Stock issued for settlement, PSU, net of tax (in shares)	116,813		72,305		113,103
Activity
Non-vested at the beginning of the period (in shares)	308,877		333,359		407,123
Granted (in shares)	379,332		98,952		128,865
Vested (in shares)	(166,672)		(105,820)		(160,398)
Forfeited (in shares)	(25,293)		(17,614)		(42,231)
Non-vested at the end of the period (in shares)	496,244		308,877		333,359
Weighted Average Grant Date Fair Value
Non-vested outstanding at the beginning of the period (in dollars per share)	$ 44.33		$ 31.16		$ 34.67
Granted (in dollars per share)	$ 49.47		$ 72.69		$ 40.31
Vested (in dollars per share)	$ 32.72		$ 30.61		$ 46.30
Forfeited (in dollars per share)	$ 51.06		$ 36.80		$ 35.43
Non-vested outstanding at the end of the period (in dollars per share)	$ 51.81		$ 44.33		$ 31.16
Stock Option Grants Under Prior Stock Option Plans [Member]
Stock Option Activity Rollforward
Stock options outstanding at the beginning of the period (in shares)	508,214		920,765		1,274,920
Issuance of common stock upon stock option exercises, including income tax benefit	(240,368)		(412,551)		(346,377)
Stock Options: Forfeitures in Period (in shares)	0		0		(7,778)
Stock options outstanding at the end of the period (in shares)	267,846		508,214		920,765
Stock Options: Weighted-average Exercise Price [Abstract]
Stock options outstanding at the beginning of the period (in dollars per share)	$ 13.86		$ 13.11		$ 13.31
Exercised (in dollars per share)	$ 12.65		$ 12.19		$ 13.77
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price	$ 0		$ 0		$ 16.66
Stock options outstanding at the end of the period (in dollars per share)	$ 14.95		$ 13.86		$ 13.11
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Exercise Price	$ 14.95		$ 13.86		$ 13.11
Stock Options: Aggregate Intrinsic Value
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value	11,842,575		24,359,240		11,281,865
Aggregate Intrinsic Value	9,983,177		30,109,110		42,192,057
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value	9,983,177		30,109,110		42,192,057
Stock Options: Additional Disclosures [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Number	267,846		508,214		920,765
Stock Option Grants Under Prior Stock Option Plans [Member] | Exercise Price Range 1 [Member]
Stock Options: Additional Disclosures [Abstract]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$ 12.53
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	33,805
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	3 months
Stock Option Grants Under Prior Stock Option Plans [Member] | Exercise Price Range 2 [Member]
Stock Options: Additional Disclosures [Abstract]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$ 12.66
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	28,053
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	9 months
Stock Option Grants Under Prior Stock Option Plans [Member] | Exercise Price Range 3 [Member]
Stock Options: Additional Disclosures [Abstract]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$ 13.39
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	17,142
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	9 months 22 days
Stock Option Grants Under Prior Stock Option Plans [Member] | Exercise Price Range 4 [Member]
Stock Options: Additional Disclosures [Abstract]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$ 13.65
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	35,893
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	6 months
Stock Option Grants Under Prior Stock Option Plans [Member] | Exercise Price Range 5 [Member]
Stock Options: Additional Disclosures [Abstract]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$ 14.25
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	104,093
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	1 year
Stock Option Grants Under Prior Stock Option Plans [Member] | Exercise Price Range 6 [Member]
Stock Options: Additional Disclosures [Abstract]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$ 20.87
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	48,860
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	2 years
Shares Issued to the Board of Directors [Member]
Performance Share Units, Restricted Stock Units, and Shares Issued to Directors [Abstract]
Stock-based compensation expense	$ 1,300,000		$ 1,200,000		$ 781,000
Stock issued from treasury to non-employee directors (in shares)	30,486		21,568		24,258
First Anniversary [Member] | Performance Shares [Member]
Performance Share Units, Restricted Stock Units, and Shares Issued to Directors [Abstract]
PSU/RSU Vesting Increment			0.14
First Anniversary [Member] | Restricted Stock Units (RSUs) [Member]
Performance Share Units, Restricted Stock Units, and Shares Issued to Directors [Abstract]
PSU/RSU Vesting Increment			0.14
Second Anniversary [Member] | Performance Shares [Member]
Performance Share Units, Restricted Stock Units, and Shares Issued to Directors [Abstract]
PSU/RSU Vesting Increment			0.29
Second Anniversary [Member] | Restricted Stock Units (RSUs) [Member]
Performance Share Units, Restricted Stock Units, and Shares Issued to Directors [Abstract]
PSU/RSU Vesting Increment			0.29
Third Anniversary [Member] | Performance Shares [Member]
Performance Share Units, Restricted Stock Units, and Shares Issued to Directors [Abstract]
PSU/RSU Vesting Increment			0.57
Third Anniversary [Member] | Restricted Stock Units (RSUs) [Member]
Performance Share Units, Restricted Stock Units, and Shares Issued to Directors [Abstract]
PSU/RSU Vesting Increment			0.57

[1] The number of awards assumes a one multiplier. The final number of shares of common stock issued may vary depending on the ending three-year performance multiplier, which ranges from zero to two.