Segment Information - Segment Reporting Information by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Segment Information [Line Items]
Revenues	$ 1,062,224	$ 1,060,991	$ 3,182,994	$ 3,164,272
Depreciation and Amortization	157,561	157,797	484,375	474,595
Depreciation	108,152	112,990	336,485	337,923
Amortization	49,409	44,807	147,890	136,672
Adjusted EBITDA	375,701	362,330	1,051,149	1,065,460
Total Assets	13,577,167	11,810,870	13,577,167	11,810,870	$ 11,857,218
Expenditures for Segment Assets	201,278	182,822	703,622	2,104,525
Capital Expenditures (see Liquidity and Capital Resources section of Management's Discussion & Analysis of Financial Condition and Results of Operations)	166,483	112,352	533,614	329,953
Cash Paid for Acquisitions, Net of Cash Acquired	11,848	44,142	56,499	1,711,011
Acquisitions of Customer Relationships, Customer Inducements and Contract Fulfillment Costs	22,947	26,328	113,509	63,561
North American Records and Information Management Business
Segment Information [Line Items]
Revenues	542,044	539,603	1,608,697	1,605,526
Depreciation and Amortization	58,801	59,869	181,494	183,591
Depreciation	45,394	46,756	137,801	144,146
Amortization	13,407	13,113	43,693	39,445
Adjusted EBITDA	246,415	248,600	715,683	719,199
Total Assets	5,742,593	4,961,149	5,742,593	4,961,149
Expenditures for Segment Assets	64,098	53,665	166,908	138,210
Capital Expenditures (see Liquidity and Capital Resources section of Management's Discussion & Analysis of Financial Condition and Results of Operations)	46,376	31,373	103,660	86,365
Cash Paid for Acquisitions, Net of Cash Acquired	0	0	9,876	1,551
Acquisitions of Customer Relationships, Customer Inducements and Contract Fulfillment Costs	17,722	22,292	53,372	50,294
North American Data Management Business
Segment Information [Line Items]
Revenues	96,552	97,477	289,714	297,472
Depreciation and Amortization	6,709	9,472	27,011	29,114
Depreciation	4,620	7,277	20,451	22,517
Amortization	2,089	2,195	6,560	6,597
Adjusted EBITDA	54,378	53,484	157,998	162,616
Total Assets	860,101	823,868	860,101	823,868
Expenditures for Segment Assets	2,822	5,033	13,708	15,529
Capital Expenditures (see Liquidity and Capital Resources section of Management's Discussion & Analysis of Financial Condition and Results of Operations)	2,822	5,033	13,708	15,529
Cash Paid for Acquisitions, Net of Cash Acquired	0	0	0	0
Acquisitions of Customer Relationships, Customer Inducements and Contract Fulfillment Costs	0	0	0	0
Western European Business
Segment Information [Line Items]
Revenues	121,437	126,354	377,517	393,869
Depreciation and Amortization	13,257	14,316	42,842	49,372
Depreciation	9,137	9,996	30,560	34,575
Amortization	4,120	4,320	12,282	14,797
Adjusted EBITDA	38,639	40,817	122,011	131,377
Total Assets	1,319,442	1,104,221	1,319,442	1,104,221
Expenditures for Segment Assets	18,125	2,774	72,560	37,813
Capital Expenditures (see Liquidity and Capital Resources section of Management's Discussion & Analysis of Financial Condition and Results of Operations)	16,191	551	41,031	31,694
Cash Paid for Acquisitions, Net of Cash Acquired	0	0	11,850	0
Acquisitions of Customer Relationships, Customer Inducements and Contract Fulfillment Costs	1,934	2,223	19,679	6,119
Other International Business
Segment Information [Line Items]
Revenues	197,728	200,639	598,507	618,933
Depreciation and Amortization	30,008	31,487	91,367	93,724
Depreciation	17,512	19,272	53,563	56,535
Amortization	12,496	12,215	37,804	37,189
Adjusted EBITDA	62,120	60,106	178,993	181,305
Total Assets	2,620,709	2,328,574	2,620,709	2,328,574
Expenditures for Segment Assets	43,290	49,330	93,373	111,777
Capital Expenditures (see Liquidity and Capital Resources section of Management's Discussion & Analysis of Financial Condition and Results of Operations)	28,944	21,929	56,048	60,992
Cash Paid for Acquisitions, Net of Cash Acquired	11,848	26,277	31,253	45,673
Acquisitions of Customer Relationships, Customer Inducements and Contract Fulfillment Costs	2,498	1,124	6,072	5,112
Global Data Center Business
Segment Information [Line Items]
Revenues	64,418	63,380	188,245	164,878
Depreciation and Amortization	34,067	27,965	98,370	72,736
Depreciation	20,193	16,431	58,233	40,931
Amortization	13,874	11,534	40,137	31,805
Adjusted EBITDA	32,261	27,299	85,913	72,990
Total Assets	2,349,917	2,159,955	2,349,917	2,159,955
Expenditures for Segment Assets	58,060	42,585	314,242	1,745,770
Capital Expenditures (see Liquidity and Capital Resources section of Management's Discussion & Analysis of Financial Condition and Results of Operations)	57,267	41,896	279,856	98,169
Cash Paid for Acquisitions, Net of Cash Acquired	0	0	0	1,645,922
Acquisitions of Customer Relationships, Customer Inducements and Contract Fulfillment Costs	793	689	34,386	1,679
Corporate and Other Business
Segment Information [Line Items]
Revenues	40,045	33,538	120,314	83,594
Depreciation and Amortization	14,719	14,688	43,291	46,058
Depreciation	11,296	13,258	35,877	39,219
Amortization	3,423	1,430	7,414	6,839
Adjusted EBITDA	(58,112)	(67,976)	(209,449)	(202,027)
Total Assets	684,405	433,103	684,405	433,103
Expenditures for Segment Assets	14,883	29,435	42,831	55,426
Capital Expenditures (see Liquidity and Capital Resources section of Management's Discussion & Analysis of Financial Condition and Results of Operations)	14,883	11,570	39,311	37,204
Cash Paid for Acquisitions, Net of Cash Acquired	0	17,865	3,520	17,865
Acquisitions of Customer Relationships, Customer Inducements and Contract Fulfillment Costs	0	0	0	357
Storage rental
Segment Information [Line Items]
Revenues	673,318	656,973	2,005,580	1,963,561
Storage rental | North American Records and Information Management Business
Segment Information [Line Items]
Revenues	317,820	306,633	938,161	917,347
Storage rental | North American Data Management Business
Segment Information [Line Items]
Revenues	66,497	67,779	199,819	205,833
Storage rental | Western European Business
Segment Information [Line Items]
Revenues	78,009	79,492	237,258	245,883
Storage rental | Other International Business
Segment Information [Line Items]
Revenues	128,715	124,920	387,086	386,278
Storage rental | Global Data Center Business
Segment Information [Line Items]
Revenues	62,001	60,039	182,301	157,479
Storage rental | Corporate and Other Business
Segment Information [Line Items]
Revenues	20,276	18,110	60,955	50,741
Service
Segment Information [Line Items]
Revenues	388,906	404,018	1,177,414	1,200,711
Service | North American Records and Information Management Business
Segment Information [Line Items]
Revenues	224,224	232,970	670,536	688,179
Service | North American Data Management Business
Segment Information [Line Items]
Revenues	30,055	29,698	89,895	91,639
Service | Western European Business
Segment Information [Line Items]
Revenues	43,428	46,862	140,259	147,986
Service | Other International Business
Segment Information [Line Items]
Revenues	69,013	75,719	211,421	232,655
Service | Global Data Center Business
Segment Information [Line Items]
Revenues	2,417	3,341	5,944	7,399
Service | Corporate and Other Business
Segment Information [Line Items]
Revenues	$ 19,769	$ 15,428	$ 59,359	$ 32,853