Retirement Benefits (Details) (USD $)	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010	Dec. 31, 2009
Retirement Benefits [Abstract]
Number of unfunded non-qualified deferred compensation pension plans	2
Years of service credited under Supplemental Executive Retirement Plan (in years)	0.5Y
Defined benefit postretirement plans [Abstract]
Number of defined benefit postretirement plans	2
Number of defined postretirement plans providing medical benefits	1
Assumed submitted claims medical trend rate used to fix the amount of the Company's obligation (in hundredths)	9.25%
Year in which submitted claims medical trend rate was determined	1997
Defined contribution retirement plans [Abstract]
Employer contribution match rate, U.S. employees (in hundredths)	75.00%
Maximum employee contribution rate matched by employer, U.S. employees (in hundredths)	6.00%
Maximum employee contribution rate over and above employee contribution rate matched by employer, U.S. employees (in hundredths)	18.00%
Incremental rate by which employee contribution rate may be increased or decreased, U.S. employees (in hundredths)	1.00%
Minimum employer contribution rate, Canadian employees (in hundredths)	3.00%
Maximum employer contribution rate, Canadian employees (in hundredths)	8.00%
Expense reocrded	$ 4,600,000		$ 3,800,000	$ 3,300,000
Other comprehensive income, pre-tax amount [Abstract]
Foreign currency translation adjustments, pre-tax amount	(3,316,000)		(960,000)	3,525,000
Other comprehensive income (loss), pre-tax amount	(65,177,000)		2,592,000	8,669,000
Other comprehensive income, tax (expense)/benefit [Abstract]
Foreign currency translation adjustments. tax (expense)/benefit	0		0
Amortization of net prior service cost, tax (expense)/benefit				0
Other comprehensive income (loss), tax (expense)/benefit	22,887,000		(1,312,000)	(1,895,000)
Other comprehensive income, net amount [Abstract]
Foreign currency translation adjustments, net amount	(3,316,000)		(960,000)	3,525,000
Other comprehensive income (loss), net amount	(42,290,000)		1,280,000	6,774,000
Accumulated other comprehensive income (loss) [Abstract]
Foreign currency translation, beginning of period	1,761,000		5,077,000	6,037,000
Foreign currency translation, current-period change	(3,316,000)		(960,000)	3,525,000
Foreign currency translation, end of period	1,761,000		5,077,000	6,037,000
Accumulated other comprehensive loss, beginning of period	(78,936,000)		(36,646,000)	(37,926,000)
Accumulated other comprehensive loss, current-period change	(42,290,000)		1,280,000	6,774,000
Accumulated other comprehensive loss, end of period	(78,936,000)		(36,646,000)	(37,926,000)
Significant Unobservable Inputs (Level 3) [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at end of year	2,156,000
Pension Benefits [Member]
Benefit obligations [Roll Forward]
Service cost	6,881,000		5,654,000	4,769,000
Interest cost	11,842,000		11,585,000	11,970,000
Fair value of plan assets [Roll Forward]
Fair value of plan assets at end of year	190,547,000
Accumulated benefit obligation	268,300,000		211,700,000
Net periodic benefit cost [Abstract]
Service cost	6,881,000		5,654,000	4,769,000
Interest cost	11,842,000		11,585,000	11,970,000
Expected return on plan assets	(13,564,000)		(12,752,000)	(12,285,000)
Amortization of prior service cost	946,000		785,000	795,000
Amortization of unrecognized net (gain) loss	3,917,000		3,712,000	4,566,000
Curtailment	0		0	1,542,000
Net periodic benefit cost (income)	10,022,000		8,984,000	11,357,000
Amounts that will be amortized from accumulated other comprehensive income into net periodic benefit cost in next fiscal year [Abstract]
Estimated net loss that will be amortized from accumulated other comprehensive income into net periodic benefit cost over the next fiscal year	8,800,000
Estimated prior service cost that will be amortized from accumulated other comprehensive income into net periodic benefit cost over the next fiscal year	900,000
Weighted average assumptions used to determine benefit obligation [Abstract]
Discount rate, minimum	4.09%		5.19%
Discount rate, maximum	4.19%		5.26%
Rate of compensation increase, minimum			5.12%
Rate of compensation increase, maximum	4.90%		5.21%
Weighted average assumptions used to determine net periodic benefit cost [Abstract]
Discount rate, minimum	5.19%		5.26%	6.00%
Discount rate, maximum	5.26%		5.80%	6.40%
Expected long-term return on plan assets	6.80%		6.80%	7.30%
Rate of compensation increase	4.90%		5.12%	4.50%
Historical compounded return period, minimum			10
Historical compounded return period, maximum			15
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year Minimum	16,000,000
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year Maximum	20,000,000
Estimated future benefit payments [Abstract]
2012	11,862,000
2013	12,504,000
2014	13,338,000
2015	14,174,000
2016	14,990,000
2017 - 2021	86,672,000
Other comprehensive income, pre-tax amount [Abstract]
Amortization of net prior service cost, pre-tax amount	946,000		785,000	795,000
Amortization of net (gain) loss, pre-tax amount	3,917,000		3,712,000	4,566,000
Net gain (loss) arising during period, pre-tax amount	(65,879,000)		(2,030,000)	(1,717,000)
Other, pre-tax amount				2,678,000
Total defined benefit pension/postretirement plans, pre-tax amount	(61,016,000)		2,467,000	6,322,000
Other comprehensive income, tax (expense)/benefit [Abstract]
Amortization of net prior service cost, tax (expense)/benefit	(350,000)		(290,000)	(293,000)
Amortization of net (gain) loss, tax (expense)/benefit	(1,449,000)		(1,371,000)	(1,682,000)
Net gain (loss) arising during period, tax (expense)/benefit	24,374,000		750,000	632,000
Other, tax (expense)/benefit				(986,000)
Total defined benefit pension/postretirement plans, tax (expense)/benefit	22,575,000		(911,000)	(2,329,000)
Other comprehensive income, net amount [Abstract]
Amortization of net prior service cost, net amount	596,000		495,000	502,000
Amortization of net (gain) loss, net amount	2,468,000		2,341,000	2,884,000
Net gain (loss) arising during period, net amount	(41,505,000)		(1,280,000)	(1,085,000)
Other, net amount				1,692,000
Total defined benefit pension/postretirement plans, net amount	(38,441,000)		1,556,000	3,993,000
Accumulated other comprehensive income (loss) [Abstract]
Defined benefit pension/postretirement plans, beginning of period	(81,813,000)		(43,372,000)	(44,928,000)
Defined benefit pension/postretirement, current-period change	(38,441,000)		1,556,000	3,993,000
Defined benefit pension/postretirement plans, beginning of period	(81,813,000)		(43,372,000)	(44,928,000)
Pension Benefits [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at end of year	75,415,000
Pension Benefits [Member] | Significant Observable Inputs (Level 2) [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at end of year	56,042,000
Pension Benefits [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at beginning of year	50,611,000
Actual return on plan assets relating to assets still held at the reporting date	321,000
Actual return on plan assets relating to assets sold during the period	0
Purchases, sales, and settlements	6,000,000
Other	2,158,000
Transfers in and/or out of Level 3	0
Fair value of plan assets at end of year	59,090,000
Pension Benefits [Member] | Cash [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at end of year	3,661,000
Pension Benefits [Member] | Cash [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at end of year	3,661,000
Pension Benefits [Member] | Common stock [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at end of year	49,234,000
Pension Benefits [Member] | Common stock [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at end of year	49,234,000
Pension Benefits [Member] | International stock - commingled funds [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at end of year	28,391,000	[1]
Pension Benefits [Member] | International stock - commingled funds [Member] | Significant Observable Inputs (Level 2) [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at end of year	28,391,000	[1]
Pension Benefits [Member] | International stock - mutual funds [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at end of year	8,465,000
Pension Benefits [Member] | International stock - mutual funds [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at end of year	8,465,000
Pension Benefits [Member] | US Treasuries [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at end of year	14,055,000
Pension Benefits [Member] | US Treasuries [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at end of year	14,055,000
Pension Benefits [Member] | Mortgage-backed securities [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at end of year	6,953,000
Pension Benefits [Member] | Mortgage-backed securities [Member] | Significant Observable Inputs (Level 2) [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at end of year	6,953,000
Pension Benefits [Member] | Collateralized mortgage obligations [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at end of year	2,156,000
Pension Benefits [Member] | Corporate bonds [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at end of year	20,698,000	[2]
Pension Benefits [Member] | Corporate bonds [Member] | Significant Observable Inputs (Level 2) [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at end of year	20,698,000	[2]
Pension Benefits [Member] | Equity long/short hedge funds [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at end of year	35,288,000	[3]
Pension Benefits [Member] | Equity long/short hedge funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at beginning of year	36,305,000
Actual return on plan assets relating to assets still held at the reporting date	(1,017,000)
Fair value of plan assets at end of year	35,288,000	[3]
Pension Benefits [Member] | Insurance policy [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at end of year	645,000	[4]
Pension Benefits [Member] | Insurance policy [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at beginning of year	643,000
Other	2,000
Fair value of plan assets at end of year	645,000	[4]
Pension Benefits [Member] | Real Estate [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at end of year	21,001,000	[5]
Pension Benefits [Member] | Real Estate [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair value of plan assets [Roll Forward]
Fair value of plan assets at beginning of year	13,663,000
Actual return on plan assets relating to assets still held at the reporting date	1,338,000
Purchases, sales, and settlements	6,000,000
Fair value of plan assets at end of year	21,001,000	[5]
Other postretirement Benefits [Member]
Benefit obligations [Roll Forward]
Service cost	129,000		92,000	145,000
Interest cost	346,000		350,000	503,000
Net periodic benefit cost [Abstract]
Service cost	129,000		92,000	145,000
Interest cost	346,000		350,000	503,000
Expected return on plan assets	0		0	0
Amortization of prior service cost	51,000		51,000	54,000
Amortization of unrecognized net (gain) loss	(223,000)		(291,000)	(217,000)
Curtailment	0		0	(145,000)
Net periodic benefit cost (income)	303,000		202,000	340,000
Amounts that will be amortized from accumulated other comprehensive income into net periodic benefit cost in next fiscal year [Abstract]
Estimated net loss that will be amortized from accumulated other comprehensive income into net periodic benefit cost over the next fiscal year	200,000
Estimated prior service cost that will be amortized from accumulated other comprehensive income into net periodic benefit cost over the next fiscal year	100,000
Weighted average assumptions used to determine benefit obligation [Abstract]
Discount rate	4.05%		4.97%
Weighted average assumptions used to determine net periodic benefit cost [Abstract]
Discount rate	4.97%		5.58%	6.25%
Estimated future employer contributions for the next fiscal year	500,000
Estimated future benefit payments [Abstract]
2012	457,000
2013	477,000
2014	490,000
2015	506,000
2016	519,000
2017 - 2021	2,649,000
Other comprehensive income, pre-tax amount [Abstract]
Amortization of net prior service cost, pre-tax amount	51,000		51,000	54,000
Amortization of net (gain) loss, pre-tax amount	(223,000)		(291,000)	(217,000)
Net prior service cost, pre-tax amount				(640,000)
Net gain (loss) arising during period, pre-tax amount	(673,000)		1,325,000	(471,000)
Other, pre-tax amount				96,000
Total defined benefit pension/postretirement plans, pre-tax amount	(845,000)		1,085,000	(1,178,000)
Other comprehensive income, tax (expense)/benefit [Abstract]
Amortization of net prior service cost, tax (expense)/benefit	(19,000)		(19,000)	(20,000)
Amortization of net (gain) loss, tax (expense)/benefit	83,000		108,000	80,000
Net prior service cost, tax (expense)/benefit				235,000
Net gain (loss) arising during period, tax (expense)/benefit	248,000		(490,000)	174,000
Other, tax (expense)/benefit				(35,000)
Total defined benefit pension/postretirement plans, tax (expense)/benefit	312,000		(401,000)	434,000
Other comprehensive income, net amount [Abstract]
Amortization of net prior service cost, net amount	32,000		32,000	34,000
Amortization of net (gain) loss, net amount	(140,000)		(183,000)	(137,000)
Net prior service cost, net amount				(405,000)
Net gain (loss) arising during period, net amount	(425,000)		835,000	(297,000)
Other, net amount				61,000
Total defined benefit pension/postretirement plans, net amount	(533,000)		684,000	(744,000)
Accumulated other comprehensive income (loss) [Abstract]
Defined benefit pension/postretirement plans, beginning of period	1,116,000		1,649,000	965,000
Defined benefit pension/postretirement, current-period change	(533,000)		684,000	(744,000)
Defined benefit pension/postretirement plans, beginning of period	$ 1,116,000		$ 1,649,000	$ 965,000

[1] Thiscategory represents International Equity Commingled Funds which invests in international stocks.Thebenchmark is the MSCI EAFE Index.

[2] This category represents investment grade bonds of U.S. issuers from diverse industries.

[3] This category includes hedge funds that invest both long and short in primarily U.S. common stocks. Management of the hedge funds has the ability to shift investments from value to growth strategies, from small to large capitalization stocks, and from a net long position to a net short position; however it is expected that the equity long/short hedge funds will have a net long position.

[4] This category includes a private insurance policy used for French retirement benefits.

[5] This category includes a RREEF America II Fund which consists of commingled private real estate.