Equity Compensation Plans - Unrecognized Compensation Cost (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2016	Dec. 31, 2016
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Unrecognized compensation cost at beginning of period	$ 23,608	$ 23,608
Equity grants		11,870
Equity grant forfeitures		(4,756)
Equity compensation expense		(12,576)
Unrecognized Compensation Cost at End of Period		18,146
Restricted Stock
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Unrecognized Compensation Cost at End of Period		2,000
Deferred Stock Units
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Equity compensation expense	(3,000)
Unrecognized Compensation Cost at End of Period		12,000
Performance Stock Units
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Equity compensation expense	(600)
Unrecognized Compensation Cost at End of Period		5,000
Incentive Plans \| Restricted Stock
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Unrecognized compensation cost at beginning of period	2,393	2,393
Equity grants		1,754
Equity grant forfeitures		(1,380)
Equity compensation expense		(676)
Unrecognized Compensation Cost at End of Period		2,091
Incentive Plans \| Deferred Stock Units
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Unrecognized compensation cost at beginning of period	14,392	14,392
Equity grants		7,416
Equity grant forfeitures		(1,167)
Equity compensation expense		(9,135)
Unrecognized Compensation Cost at End of Period		11,506
Incentive Plans \| Performance Stock Units
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Unrecognized compensation cost at beginning of period	6,823	6,823
Equity grants		2,576
Equity grant forfeitures		(2,209)
Equity compensation expense		(2,641)
Unrecognized Compensation Cost at End of Period		4,549
Employee Stock Purchase Plan
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Unrecognized compensation cost at beginning of period	$ 0	0
Equity grants		124
Equity grant forfeitures		0
Equity compensation expense		(124)
Unrecognized Compensation Cost at End of Period		$ 0

Allocated Share-based Compensation Expense, Including Restructuring

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- Definition

Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]

+ References

No definition available.

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- Definition

Represents the amount of equity grant forfeitures during the period.

+ References

No definition available.

+ Details

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- Definition

Represents the compensation cost capitalized during the period arising from equity-based compensation arrangements (for example, shares of stock, units, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(ii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Unrecognized cost of unvested share-based compensation awards.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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