Stock-Based Compensation (Details)		4 Months Ended	8 Months Ended	12 Months Ended
	Aug. 17, 2015 $ / shares shares	Dec. 31, 2015 USD ($) plan $ / shares shares	Aug. 16, 2015 $ / shares shares	Dec. 31, 2015 USD ($) shareholder plan $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Dec. 31, 2013 USD ($) $ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of share-based compensation plans covering employees, officers and directors | plan		5		5
Expiration period of stock options (in years)				10 years
Post spin trading day average used for conversion ratio, period	10 days
Shareholders impacted by conversion | shareholder				120
Stock Option, Intrinsic Value
Weighted average grant date fair value of options (in dollars per share) | $ / shares		$ 5.89		$ 5.89	$ 4.37	$ 9.25
Employee Benefit Plan
Maximum 401(K) plan contribution by employer as a percent of employee's salary				3.50%
Aggregate employer 401(K) plan contribution during the period | $				$ 1,227,000	$ 1,136,000	$ 1,036,000
Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for issuance		2,970,350		2,970,350
Number of shares available for future issuance		2,890,457		2,890,457
Nonvested Restricted Stock and Restricted Stock Units, Weighted Average Grant Date Fair Value
Number of shares purchased		79,893		79,893
Employee Stock | Employee
Nonvested Restricted Stock and Restricted Stock Units, Weighted Average Grant Date Fair Value
Discount related to the Employee Stock Purchase Plan				90.00%
Employee Stock | Director
Nonvested Restricted Stock and Restricted Stock Units, Weighted Average Grant Date Fair Value
Discount related to the Employee Stock Purchase Plan				95.00%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)				2 years
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)				3 years
Stock Options
Fair value assumptions of stock options using Black-Scholes option pricing model
Risk-free interest rate, minimum (as a percent)				1.02%	1.30%	0.59%
Risk-free interest rate, maximum (as a percent)				1.38%	1.40%	0.63%
Dividend yield (as a percent)				5.00%	5.00%	5.00%
Volatility factors of the expected market price for our common stock, minimum (as a percent)				19.00%	17.80%	24.20%
Volatility factors of the expected market price for our common stock, maximum (as a percent)				20.00%	18.00%	31.70%
Weighted average expected life of options, maximum (in years)				4 years	4 years 2 months 1 day
Stock Option, Shares
Outstanding at the beginning of the period (in shares)	3,107,929	3,084,457	2,460,628	2,460,628
Granted (in shares)		0	792,434
Options exercised (in shares)		20,814	130,273
Options forfeited (in shares)		11,914	12,058
Options expired (in shares)		0	2,802
Options forfeited/expired (in shares)	511,832
Options issued at spin (in shares)	488,360
Outstanding at the end of the period (in shares)	3,084,457	3,051,729	3,107,929	3,051,729	2,460,628
Exercisable at the end of the period (in shares)		2,183,113		2,183,113
Stock Option, Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share) | $ / shares	$ 62.90	$ 52.51	$ 57.45	$ 57.45
Options granted (in dollars per share) | $ / shares		0.00	76.62
Options exercised (in dollars per share) | $ / shares		35.13	43.30
Options forfeited (in dollars per share) | $ / shares		55.67	62.47
Options expired (in dollars per share) | $ / shares		0.00	66.43
Options forfeited/expired (in dollars per share) | $ / shares	65.51
Options issued (in dollars per share) | $ / shares	52.51
Outstanding at the end of the period (in dollars per share) | $ / shares	$ 52.51	52.62	$ 62.90	52.62	$ 57.45
Exercisable at the end of the period (in dollars per share) | $ / shares		$ 49.73		$ 49.73
Stock Option, Weighted Average Remaining Contractual Life (years)
Outstanding at the end of the period (in years)				7 years 11 days
Exercisable at the end of the period (in years)				6 years 4 months 10 days
Stock Option, Intrinsic Value
Outstanding at the end of the period | $		$ 18,216,000		$ 18,216,000
Exercisable at the end of the period | $		16,815,000		16,815,000
Unrecognized compensation cost related to nonvested awards | $		1,800,000		$ 1,800,000
Weighted average period over which cost is recognized (in years)				1 year 2 months 19 days
Proceeds from options exercised | $				$ 6,400,000	$ 26,200,000	$ 7,200,000
Intrinsic value for options exercised | $				4,700,000	19,300,000	$ 4,000,000
Stock Options | Minimum
Fair value assumptions of stock options using Black-Scholes option pricing model
Weighted average expected life of options, maximum (in years)						4 years 3 months
Stock Options | Maximum
Fair value assumptions of stock options using Black-Scholes option pricing model
Weighted average expected life of options, maximum (in years)						7 years
Stock Options | General and administrative expenses
Stock Option, Intrinsic Value
Compensation cost | $				4,200,000	4,700,000	$ 4,500,000
Restricted Stock or Restricted Stock Units
Stock Option, Intrinsic Value
Unrecognized compensation cost related to nonvested awards | $		9,300,000		$ 9,300,000
Weighted average period over which cost is recognized (in years)				1 year 6 months 4 days
Nonvested Restricted Stock and Restricted Stock Units, Weighted Average Grant Date Fair Value
Intrinsic value for options vested during period | $		$ 18,300,000		$ 18,300,000	17,700,000	16,900,000
Restricted Stock or Restricted Stock Units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)				2 years
Restricted Stock or Restricted Stock Units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)				5 years
Restricted Stock or Restricted Stock Units | General and administrative expenses
Stock Option, Intrinsic Value
Compensation cost | $				$ 15,200,000	$ 16,200,000	$ 16,100,000
Restricted Stock
Nonvested Restricted Stock and Restricted Stock Units, Shares
Nonvested at the beginning of the period (in shares)		350,107	402,741	402,741
Granted (in shares)	54,364	31,176	190,429
Vested (in shares)		3,323	237,461
Forfeited (in shares)	61,166	8,065	5,602
Nonvested at the end of the period (in shares)	350,107	363,093		363,093	402,741
Nonvested Restricted Stock and Restricted Stock Units, Weighted Average Grant Date Fair Value
Nonvested at the beginning of the period (in dollars per share) | $ / shares		$ 65.53	$ 58.51	$ 58.51
Granted (in dollars per share) | $ / shares	$ 2.34	56.12	75.46
Vested (in dollars per share) | $ / shares		50.49	61.69
Forfeited (in dollars per share) | $ / shares	64.94	52.57	$ 61.12
Nonvested at the end of the period (in dollars per share) | $ / shares	$ 65.53	$ 57.65		$ 57.65	$ 58.51
Restricted Stock Units
Nonvested Restricted Stock and Restricted Stock Units, Shares
Nonvested at the beginning of the period (in shares)		11,788	11,392	11,392
Granted (in shares)	2,216	0	7,252
Vested (in shares)		0	6,856
Forfeited (in shares)	0	0	0
Nonvested at the end of the period (in shares)	11,788	25,500		25,500	11,392
Nonvested Restricted Stock and Restricted Stock Units, Weighted Average Grant Date Fair Value
Nonvested at the beginning of the period (in dollars per share) | $ / shares		$ 66.15	$ 58.79	$ 58.79
Granted (in dollars per share) | $ / shares	$ 2.34	0.00	71.70
Vested (in dollars per share) | $ / shares		0.00	59.79
Forfeited (in dollars per share) | $ / shares	0.00	0.00	$ 0.00
Nonvested at the end of the period (in dollars per share) | $ / shares	$ 66.15	$ 58.02		$ 58.02	$ 58.79
2012 Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for issuance		10,499,135		10,499,135
Number of shares available for future issuance		7,876,301		7,876,301
Executive Deferred Stock Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of share-based compensation plans for executive officers | plan		1		1
Number of shares authorized for issuance		594,070		594,070
Number of shares available for future issuance		594,070		594,070
Nonemployee Directors' Deferred Stock Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of share-based compensation plans for directors | plan		1		1
Number of shares authorized for issuance		594,070		594,070
Number of shares available for future issuance		478,048		478,048
Spinoff | CCP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of vested awards granted | $		$ 3,500,000
Fair value of unvested awards granted | $		$ 1,600,000