Stock and Other Incentive Plans - Narrative (Details)										3 Months Ended			12 Months Ended
	Dec. 12, 2019 USD ($) executive_officer shares	Sep. 30, 2019 USD ($) shares	Dec. 12, 2018 USD ($) shares	Dec. 11, 2017 USD ($) executive_officer shares	Dec. 30, 2016 USD ($) shares	Dec. 16, 2016	Mar. 01, 2016 USD ($) shares	Feb. 16, 2016	Jul. 31, 2012	Mar. 31, 2019 USD ($) executive_officer shares	Dec. 31, 2018 shares	Mar. 31, 2018 USD ($) executive_officer shares	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($) shares	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 USD ($) executive_officer shares	Dec. 31, 2016 Awards	Dec. 31, 2015 shares	Dec. 31, 2014
401(k) Plan [Abstract]
Percentage of matching contribution																		3.00%
Value of matching contribution																		$ 500,000	$ 400,000	$ 400,000
Former Executive Chairman [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accelerated stock compensation expense		$ 2,900,000
Withheld of common stock (shares) | shares		80,490
Employee Stock Purchase Plan [Member]
401(k) Plan [Abstract]
Value of shares available for grant each year																		$ 25,000
Discount on market price on the date of grant																		85.00%
Discount on market price on the date of exercise																		85.00%
Option expiration period																		27 months
Cash received from employees upon exercising options																		$ 1,000,000.0	$ 400,000	$ 800,000
Deferral Option One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Salary Deferral Plan employer matching contribution, percent																		30.00%
Deferral Option Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Salary Deferral Plan employer matching contribution, percent																		50.00%
Deferral Option Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Salary Deferral Plan employer matching contribution, percent																		100.00%
2015 Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Authorization of common shares to issue (shares) | shares																		3,500,000
Common shares issued, net of forfeitures (shares) | shares																		1,988,079	1,711,240
Number of shares authorized (shares) | shares											1,788,760							1,511,921	1,788,760
2015 Incentive Plan [Member] | Restricted Stock [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period																		3 years
2015 Incentive Plan [Member] | Restricted Stock [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period																		8 years
Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares issued, net of forfeitures (shares) | shares																						1,878,637
Granted in period (in shares) | shares																		276,839	273,012	413,489
Stock Incentive Plan [Member] | Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accelerated stock compensation expense																		$ 3,500,000	$ 1,700,000	$ 1,700,000
Number of one-time non-vested share grants | Awards																					3
Stock Incentive Plan [Member] | Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accelerated stock compensation expense																		$ 800,000
Award vesting period																		1 year					3 years
Shares issued under the plan (shares) | shares																		24,996	30,989	23,231
Stock Incentive Plan [Member] | Chief Financial Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accelerated stock compensation expense							$ 200,000
Award vesting period							10 years
Granted in period (in shares) | shares							50,000
Stock Incentive Plan [Member] | President and Chief Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accelerated stock compensation expense					$ 600,000
Award vesting period					10 years
Granted in period (in shares) | shares					200,000
Stock Incentive Plan [Member] | Executive Chairman [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accelerated stock compensation expense		$ 2,000,000.0			$ 900,000
Award vesting period					5 years
Granted in period (in shares) | shares					150,000
Stock Incentive Plan [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accelerated stock compensation expense																		$ 12,000,000.0	$ 10,400,000	$ 9,800,000
Withheld of common stock (shares) | shares																		101,580	151,353	94,403
Stock Incentive Plan [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Value of performance based awards released										$ 1,000,000.0		$ 1,200,000
Shares issued under the plan (shares) | shares										31,262		43,414
Stock Incentive Plan [Member] | Performance Shares [Member] | Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of executive officers granted awards | executive_officer										4		4
Stock Incentive Plan [Member] | Performance Shares [Member] | Senior Vice President [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of executive officers granted awards | executive_officer										5		5
Stock Incentive Plan [Member] | Performance Shares [Member] | Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accelerated stock compensation expense																		$ 1,100,000	$ 1,200,000	$ 1,100,000
Stock Incentive Plan [Member] | Performance Shares [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period											3 years
Stock Incentive Plan [Member] | Performance Shares [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period											8 years
Stock Incentive Plan [Member] | Performance Shares [Member] | Weighted Average [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period											6 years
Stock Incentive Plan [Member] | Restricted Stock and Performance Based Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average amortization period remaining																		5 years
Stock Incentive Plan [Member] | Restricted Stock and Performance Based Awards [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period																		1 year
Stock Incentive Plan [Member] | Restricted Stock and Performance Based Awards [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period																		8 years
Executive Incentive Plan [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accelerated stock compensation expense																		$ 5,700,000	5,700,000	$ 5,000,000.0
Executive Incentive Plan [Member] | Performance Shares [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shareholder return performance period used to measure award									1 year
Executive Incentive Plan [Member] | Performance Shares [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shareholder return performance period used to measure award									3 years
Executive Incentive Plan [Member] | 2019 Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	5 years
Granted in period	$ 6,100,000
Granted in period (in shares) | shares	187,072
Executive Incentive Plan [Member] | 2019 Performance Shares [Member] | Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of executive officers granted awards | executive_officer	4
Executive Incentive Plan [Member] | 2019 Performance Shares [Member] | Senior Vice President [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of executive officers granted awards | executive_officer	5
Executive Incentive Plan [Member] | 2019 Performance Shares [Member] | First Vice President [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of executive officers granted awards | executive_officer	5
Executive Incentive Plan [Member] | 2018 Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accelerated stock compensation expense																		1,000,000.0
Award vesting period			5 years
Granted in period			$ 5,000,000.0
Granted in period (in shares) | shares			165,261
Executive Incentive Plan [Member] | 2018 Performance Shares [Member] | First Vice President [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of executive officers granted awards | executive_officer	5
Executive Incentive Plan [Member] | 2017 Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accelerated stock compensation expense																		2,000,000.0
Award vesting period				5 years
Granted in period				$ 10,100,000
Granted in period (in shares) | shares				309,874
Executive Incentive Plan [Member] | 2017 Performance Shares [Member] | Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of executive officers granted awards | executive_officer				5
Executive Incentive Plan [Member] | 2017 Performance Shares [Member] | First Vice President [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of executive officers granted awards | executive_officer																				4
Executive Incentive Plan [Member] | 2016 Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period						5 years
Executive Incentive Plan [Member] | 3-year Vesting [Member] | February 2016 Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period								3 years
Executive Incentive Plan [Member] | 5-year Vesting [Member] | February 2016 Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period								5 years
Executive Incentive Plan [Member] | Forecast [Member] | 2019 Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accelerated stock compensation expense													$ 1,100,000	$ 1,200,000	$ 1,200,000	$ 1,200,000	$ 1,200,000
Executive Incentive Plan [Member] | Forecast [Member] | 2018 Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accelerated stock compensation expense														$ 900,000	1,000,000	1,000,000	1,000,000
Executive Incentive Plan [Member] | Forecast [Member] | 2017 Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accelerated stock compensation expense															$ 1,900,000	$ 2,000,000	2,000,000
Executive Incentive Plan [Member] | Forecast [Member] | 2016 Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accelerated stock compensation expense																	1,300,000
Executive Incentive Plan [Member] | Forecast [Member] | February 2016 Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accelerated stock compensation expense																	$ 700,000
Salary Deferral Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accelerated stock compensation expense																		$ 900,000	$ 1,000,000.0	$ 1,200,000
Shares issued under the plan (shares) | shares																		33,509	33,348	39,016
Maximum salary deferral for officers under the plan, percent																		50.00%
Salary Deferral Plan [Member] | Deferral Option One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period																		3 years
Salary Deferral Plan [Member] | Deferral Option Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period																		5 years
Salary Deferral Plan [Member] | Deferral Option Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period																		8 years
Dividend Reinvestment Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Authorization of common shares to issue (shares) | shares																		1,000,000
401(k) Plan [Abstract]
Total DRIP shares issued under the Plan (shares) | shares																		599,104
Total shares issued under the Dividend Reinvestment Plan (shares) | shares																		7,990	9,487	26,031
General and Administrative Expense [Member] | Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accelerated stock compensation expense																		$ 200,000	$ 300,000	$ 200,000